DRIVER_IRQL_NOT_LESS_OR_EQUAL - Windows 7

DRIVER_IRQL_NOT_LESS_OR_EQUAL - Windows 7

There are many reasons why your system may crash due to a DRIVER_IRQL_NOT_LESS_OR_EQUAL STOP or BSOD (Blue Screen of Death) error, so this guide will provide some common tips that may solve the problem, along with some troubleshooting advice.

This error message means that the system attempted to access pageable memory using a kernel interrupt request level (IRQL) that was too high. This is one of the most common errors and has many possible causes, but the most common scenarios are:

• Faulty drivers
• Hardware issue
• Anti-virus software problem
• Overclocking too far

If you notice any filenames mentioned on the blue screen, googling for the filename may indicate if it is attached to any driver or software package. This can pinpoint the driver which you need to update. SCSI, Network and graphics drivers are often the offenders if this is a driver problem - so you can try updating all your drivers manually if it is difficult to track down the problem.



It is possible to analyse a "dump file" which contains more detailed information about the crash. These dump file are located in C:\Windows\MiniDump and can be opened using diagnostic packages or posted to the forums for analysis by an expert. This extra information will often provide a good clue to the BSOD crash.



If you aren't able to boot in to Windows 7 to fix the problem, you may be able to boot using safe mode (press F8 during startup, or follow this guide) and access Windows again. If this still doesn't work, try selecting the "Last known good configuration" option. If this also fails, using system restore to roll back your system a few days may be a valid option. You can use your Windows 7 installation DVD to boot to the recovery options menu, then select "System Restore".



Hardware issues are more difficult to diagnose, but if you have resorted to a clean install of Windows 7 and the problem still occurs, then it is a possibility. Memory is a frequent culprit, so you can use a tool like MemTest (or the Windows 7 memory diagnostics) to check your RAM for problems. Replacing components is often the only foolproof way to check for faults.

Memory Testing - Windows 7

Memtest86+ Memory Testing - Windows 7

If you require a more detailed memory test than that provided by the default Windows Memory Diagnostics, Memtest86+ is an excellent option. It is a well maintained, freeware application which can run on almost any hardware. This is a useful tool to run when troubleshooting suspect memory problems.



First, visit the Memtest86+ homepage to download the software. If you have a blank USB stick, it is recommended that you download the Auto-Installer for USB Key version. Otherwise, you can download the Pre-Compiled Bootable ISO and burn it to CD.

If you are creating a USB version:



Once downloaded, open up the zip file and run the .exe file to begin the installation process. You'll need accept the license agreement, then insert a blank USB drive and make sure the "format" box is checked (this will remove any data on the USB drive). When you are ready, click the Create button:

 

If you are creating the CD ISO version:



Open the zip download and extract the ISO file, then right click the ISO file and select Open With > Windows Disc Image Burner. Insert a blank CD, select the appropriate drive and then click Burn:

 

Now, restart your computer and boot from the CD/USB Drive. Within a few moments, memtest86+ will load and immediately begin testing. You can leave this running for as long as you like, but wait for around 10 passes without fault before stopping the test, just to be sure. This could take many hours, so it is suggested to leave the test running overnight:

If you have any errors, it would be beneficial to detect which stick(s) of memory (or slots) are causing the problem. You will need to test all memory sticks individually (where there are no motherboard requirements for matched pairs).



Each stick should be tested in a new slot, so that if errors occur you can isolate if the problem is due to a memory stick or slot. For example, if RAM stick #2 fails in slot #2, try stick #1 in slot #2, then stick #2 in slot #1. This swapping should then be able to identify the problem further.

How to use CHKDSK (Check Disk) - Windows 7

How to use CHKDSK (Check Disk) - Windows 7

Windows 7 includes a disk checking tool called CHKDSK which is similar to the "scandisk" tool from older versions of Windows. This application scans your hard drives for errors such as lost sectors, bad sectors and corruption.

You can launch CHKDSK using two methods (the former being the easiest):

Graphical Interface:

Open the Computer option from the start menu, which will display all of the drives available to scan on your PC:

Then, right click on the drive you wish to scan for errors and select Properties:

Now click the Tools menu, then Check Now under the error-checking section:

You have several options within the check disk tool. It is always recommended you leave the "automatically fix file system errors" box checked, as this repairs and problems found. If you want to perform a deeper scan, tick "scan for and attempt recovery of bad sectors". This second option takes longer, but is worth doing if you suspect a drive problem. Once you are configured, click Start:

If you try to check a disk that is currently in use, you will receive a message asking if you wish to schedule a scan. Accepting this will perform the scan next time you restart your PC:

Command Prompt Method:



Alternatively, you can use the command prompt to perform a scan on a drive letter of your choice by running "chkdsk x:" where x is your drive letter. The manual scan options are:

• /F Fixes errors on the disk.
• /V On FAT/FAT32: Displays the full path and name of every file on the disk. On NTFS: Displays cleanup messages if any.
• /R Locates bad sectors and recovers readable information (implies /F).
• /L:size NTFS only: Changes the log file size to the specified number of kilobytes. If size is not specified, displays current size.
• /X Forces the volume to dismount first if necessary. All opened handles to the volume would then be invalid (implies /F).
• /I NTFS only: Performs a less vigorous check of index entries.
• /C NTFS only: Skips checking of cycles within the folder structure.
• /B NTFS only: Re-evaluates bad clusters on the volume (implies /R)

"CHKDSK x: /F /R" would perform a full scan (including bad sectors) and attempt to fix them.