Repair Corrupted Windows 7, 8 & 10 System Files Using the System DISM Tool

Time to share another useful Microsoft Windows command-line utility tool. If you have experienced the "Blue Screen of Death", a crash, service pack installation failure, windows update failures or observed general Windows system file corruption error messages, then this utility tool might be useful to you.

Many common Windows Update errors which result from new system file corruption can be corrected using the Windows DISM.exe tool. Failed application or update installs often result in corruption of some of the system files. These utilities are designed to detect corrupted file and repair them. It targets the currently running operating system for repair. The DISM tool must be run from the Windows Command prompt (cmd), with an account that has administrator privileges using " Run as administrator ".

DISM = Windows "Deployment Image Servicing and Management" tool.

• Before using any software utility program, make sure you first have permission and authorization to do so. Most Importantly of all: Back up your system programs and any data files before using any utilities such as this one. Create a Restore Point to protect the basic settings too. Do this now. Take precautions before using any utility programs and do so at your own risk. You are responsible for your data, programs and computer.
  

• Please make sure you have reviewed my earlier article on how to run the System File Checker (SFC) tool first. The SFC tool scans Windows operating system files for corruption AND restores any found corrupted files, all automatically! The SFC often quickly corrects many system errors and I always run that utility first. DISM is more thorough, but takes more time to run.

• Before using the DISM (or SFC) utilities, set a new restore point using the very useful "Restore Point" feature found in Windows (discussed in an earlier post). Make sure you have enough time available for the computer to run this utility (overnight is best). Once started, it will show a progress bar. Do not interrupt the process.
  

To run the DISM.exe utility, close down all applications for now. Make sure your account has Administrator privileges, then open up the Command Prompt using the " Run as administrator " option (you must do this so the system32 path is selected). 

At the command line prompt, Type the command line below (make sure to include the spaces, exactly as shown): 

 DISM /Online /Cleanup-image /Restorehealth  

 Optionally, for some O/S enter:  DISM.exe /Online /Cleanup-image /Restorehealth 

The screen should show " Deployment Image Servicing and Management Tool " with the version #. Image Version plus some [ ] showing the progress. When it is finished, it should report that "The operation completed successfully". Type 'EXIT' to close the Command Prompt screen, then Reboot your computer.

 

 

References:

1.  Microsoft Windows Support Page:

Fix Windows Update errors by using the DISM or System Update Readiness tool 

 

2.  If you encounter "error 87", then please confirm you have: typed the command line as shown; are running the cmd "as administrator"; have applied all new or pending Windows Updates and have run the SFC tool first. If you continue to see the error, then refer to Microsoft's knowledge base for additional tips.

Capillary Electrophoresis (CE) Troubleshooting Tips:

What follows is a short list of problems, "observations" followed by a list of areas that should be investigated, as appropriate in parenthesis (), to troubleshoot common problems seen when using the analytical technique of capillary electrophoresis, CE, CZE.

 Observation (Investigate for cause):

            Excessive Baseline Drifting up or down

·         Temperature is not stable (stabilize room and/or capillary temperature).

·         Fouling of capillary (replace or clean and wash capillary with fresh, filtered solution).

·         Current levels unstable (loose connections, partial obstruction in capillary or running out of buffer solutions).

·         Capillary may have poorly cut ends resulting in poor connections or flow (replace capillary).

Excessive Signal Noise

·         Detector has air in flow cell (purge capillary and wash flow path).

·         Current level may be too high (reduce current).

·         Detection parameters, wavelength and bandwidth, may be inappropriate for buffer solution (select appropriate detection settings which are appropriate for the buffer used and selective for the analyte).

Loss of Signal

·         Voltage/Current has turned off (turn ON or investigate if system is in “alarm” state due to an error).

·         Detector parameters not selected.

·         Capillary has not been fully equilibrated (equilibrate capillary and auto-zero the scale).

·         Baseline offset may be off-scale (after equilibration, adjust scale or auto-zero).

·         Detector lamp(s) off, not ignited or due for replacement (verify lamp operation).

Signal Peak Shape Issues

·         Truncated, clipped or ‘square’ peaks (sample overload, reduce concentration 10x, shorten load time and re-evaluate).

·         Tailing peaks often result from very high current or when the concentration of buffer is too high (lower the current and/or reduce the buffer concentration, then re-evaluate).

·         Sampling rate may be too low (measure the peak width in units of time (i.e. seconds), then configure the detector to insure that the sampling rate allows for at least 20 points to be collected per average peak width (30 points is a better target # to use).

·         No peaks observed (Many possible causes, including: Partially or fully obstructed capillary, broken capillary, out of buffer, no injection, detector settings inappropriate for analysis, current too low, pressure too low. Look for a small peak from the injection along the start of the baseline to confirm that an analysis was started, then troubleshoot the method and settings).

            General Stability and Noise Issues 

·   When the CE system has not been used in a few days, salts from the buffer solution(s) may deposit on and clog the capillary line, flow cell and/or sensors. To avoid these problems, be sure to thoroughly clean, flush and wash down the flow path before use. Take the time to prepare fresh filtered solutions (each day) and allow time for the system to equilibrate. Taking these basic steps will avoid many hours/days of frustration.

Vespel, Tefzel or PEEK Valve Rotor Seals ?

One of the most common HPLC preventative maintenance parts is the injector valve rotor seal. Worldwide, the majority of these chromatography parts are produced by Rheodyne (IDEX) or Valco Instruments (VICI) and used by the major instrument manufacturers in their products. These valve seals are critical to maintaining a leak free, high pressure seal inside the injector. They are subjected to a lot of wear and chemical exposure with use. They have a finite lifetime which may be very short, in some applications (a few months) or last for many years in others. *The most common reason for rotor seal damage is a lack of flushing when buffers are used. Regular flushing down of the flow path (without the buffer) is required to maintain a clean flow path. Buffer deposits and crystals scratch and damage the rotor surfaces. Depending on the specific use and application, rotor seals are often replaced as a preventative measure once every 6 or 12 months. They should also be replaced whenever they are scratched, heavily worn, no longer sealing well, leak or become contaminated. Failure to maintain your injector's parts may lead to HPLC carry-over contamination problems.

The choice of rotor seal material should be based on: (1) the types of chemicals it will come into contact with; (2) the working pH range; (3) the temperature range.

• Note: When choosing a valve rotor seal material, please refer to the valve manufacturer's information, compatibility and advice. Blends and properties may vary between vendors so always verify compatibility with them before use.

 
Common HPLC Rotor Seal Material Types:

 Vespel ^®: Chemically, this is a polyimide blend (DuPont). One of the most widely used materials for HPLC valve rotor seals. It has excellent chemical compatibility with most HPLC mobile phases, excellent temperature stability and a pH limit of 10. An excellent choice for most applications.

Tefzel ^®: Chemical name, ethylene-tetrafluoroethylene (aka, "ETFE"). It has excellent chemical compatibility with most HPLC mobile phases and a higher pH limit of 14. Tefzel's preferred applications are where very high (>9) or very low (<3) pH solutions or mobile phases are used. Not compatible with some chlorinated solvents and in most forms it has a temperature limit of 50°C.

PEEK: Chemical name, polyether-ether ketone. Known for applications where biocompatibility and / or high temperatures are of concern. Like Tefzel, it has excellent chemical compatibility at room temperature with most HPLC mobile phases. Most vendors report a working pH range between 1 and 14. Unlike Tefzel, it has a much higher temperature limit (i.e. 100°C or higher), but its resistance to some chemicals appear to degrade with increasing temperature. Contraindicated where it will come into contact with solutions of THF, methylene chloride, DMSO or concentrated acids (i.e. nitric or sulfuric). Some sources have observed problems with chloroform as well, especially with PEEK tubing, so it may not be recommended for those applications.

 

For more information on troubleshooting HPLC injector valves, please refer to this linked article, "Troubleshooting HPLC Injectors (Manual and Automated)". 

HPLC Maintenance & Repair Parts To Have on Hand for HPLC Systems

HPLC (UHPLC) systems are complex instruments which require periodic inspection, cleaning and maintenance. These tasks are critical to maintain the performance, reliability and accuracy of the instrument. If you have not done so already, I strongly recommend that you create formal standard operating procedures (SOP's) which address: (1) The frequency of when routine and non-routine maintenance procedures should be performed; (2) The types of maintenance and/or repair procedures used (e.g. piston seal replacement, A/I rotary valve seal replacement); (3) The exact step-by-step procedure to follow in performing these tasks and (4) The Performance Verification or Qualification steps and procedures which are to be performed to verify that any repairs made have been done correctly. *An instrument log book should be employed to document these procedures over time.

Periodic "General Maintenance" of the HPLC is one type of service procedure which should be scheduled at a set frequency (Example: Every 6 months) and will serve to provide a time to clean, inspect and repair/replace any parts which are worn due to normal use. Such routine HPLC maintenance is often referred to as a basic "Preventative Maintenance" service (or "PM Service"). Spare parts common to your HPLC system(s) should be on hand to perform these scheduled maintenance procedures as part of a normal PM service.

Here is a list of common parts that should be on hand for a "typical" HPLC system used in a pharmaceutical laboratory. Please consult the appropriate manufacture's product literature to determine the correct parts needed for your own HPLC system. This list is presented as a general guideline only:

• Capillary tubing, fittings (nuts and ferrules): Assorted fittings, usually made of 316 Stainless Steel, but could be made of polymeric materials. Always have spare precut and polished chromatography tubing of appropriate I.D. and lengths for use with your HPLC available at all times. Insure that the nuts and ferrules used are appropriate for your brand of HPLC system and the columns used as different manufacturers have different specifications for their fittings and ferrules. Many types are not interchangeable.

• Detector Lamps: At least one spare bulb of a type designed for your specific detector should be on hand. Note that some detectors use multiple lamps so you may need to have more than one type available for each detector. Some lamp bulb types (e.g. tungsten) can be safely stored and last for several years while other types, such as Deuterium bulbs, loose substantial energy after as little as 6 months. If you have several detectors of the exact same design, then there is often no need to stock multiple replacement bulbs for each one. Instead, stock enough bulbs to service one detector as it is unlikely you would see failure of more than one detector on the same day (an exception to this guideline is if you perform PM services on all of the instruments at the same time, then you may want to have multiple bulbs available).

• Pump Pistons: One set of spare new pistons should be kept on hand for each pump module. As with lamp bulbs, if you have several identical pumps, then there is often no need to stock multiple sets of pistons for each one. Stock only as many as you expect to use in one year. Clean and inspect the pistons during each PM for any signs of scratches or surface abrasions. Under routine use, pistons should only require general cleaning and last a long time before replacement is required (> 1 year). Mobile phases which contain high concentrations of salt buffers often accelerate this wear requiring more frequent replacement. *Always install new piston seals when replacing pistons.

• Pump Piston Seals: At least one set of spare new piston seals should be on hand for each pump module. Seals wear out more frequently than pistons. You should go through two or more sets of piston seals before you need to replace the pistons. If the piston seals leak, inspect the pistons for wear (replace with new ones or clean and reuse) and install new piston seals. Mobile phases which contain high concentrations of salt buffers often accelerate this wear.

• Solvent Pickup Filters: These are the large particle filters which sit inside your solvent or mobile phase bottles. They are often made from stainless steel or sintered glass with porous inlets (~10 to 30 micron) and can clog or become fouled over time (esp. when used with aqueous buffers). In some cases these can be cleaned using sonication (not sintered glass filters, only steel or polymeric!). Note: Sometimes it is most cost effective to replace them with new filters then clean and re-use them.

• Inline Frits/Filters: You may have an inline filter placed after your PUMP head, but before the column inlet to collect any remaining particulate matter. These filters can extend the lifetime of the entire HPLC system (esp. the A/S, A/I and Column), but will only do so if changed on a regular basis. Some manufacturers incorporate this type of filter into the design of their pump modules. An example of this can be found on the HP/Agilent brand model 1050, 1100 and/or 1200-series pumps. These have an inexpensive 10 micron PTFE frit installed in the outlet valve of the pump. This filter catches all of the normally occurring piston seal debris and larger mobile phase particles and should be changed every month. Other pre-filters are installed in cartridges just before the column inlet. These often overlooked pre-filters filters must be replaced about once each month to do their job properly. Keep plenty of spare filters on hand.

• Auto-injector Rotary Valve Seals: If you have an auto-injector, then a high pressure valve is probably used to switch the sample into the flow path for analysis. This valve will have one or more parts which require regular inspection, cleaning and periodic replacement. Mobile phases which contain high concentrations of salt buffers often accelerate this wear. The valve rotor seal is the most common part which requires replacement.

• Auto-Sampler Needle: A needle should last a very long time, but depending on the frequency of use and type of vial septa encountered it can require replacement at regular intervals. A good general guideline would be to keep one spare needle on hand for every 2-4 systems.

• Auto-Sampler Needle Seat: The needle seat often requires more frequent replacement than the needle due to repeated mechanical wear. A good general guideline would be to keep one spare needle seat on hand for each system.

• UV/VIS Detector Flow Cell: While not actually a required PM spare part, this one is worthwhile to have. If you employ a UV/VIS flow cell, then I always suggest you keep one dedicated spare flow cell on hand which matches the size and volume of the type you use in your instrument. A spare flow cell can prove to be very valuable as a troubleshooting tool if you believe that you have contaminated or clogged your current flow cell. A quick swap can answer the question and get you back to work quickly saving hours or days of lost time. *Note: This extra flow cell should be kept separate from all instruments for use as a tested spare only and not used for regular analysis.

If you have suggestions for other types of common HPLC spares to add to the list or to have on hand, then please let me know.