• I have installed Windows 7, but after about 5 minutes the PC will consistently get a blue screen stating ''DRIVER_IRQL_NOT_LESS_THAN_EQUAL''.  It mentions kl1.sys, which after looking at the internet seems to belong to Kaspersky Anti-Virus.   Has anyone else also experienced this issue?

    Any help would be appreciated.

    • Moved by OthorvathMVP, Moderator Friday, January 16, 2009 11:04 PM (Moved from Windows 7 Installation, Setup, and Deployment to Windows 7 Application Compatibility)
    Thursday, January 15, 2009 10:19 AM


All replies

  • I forgot to mention, that this is a re-installation of Windows 7 - a fresh install.  I had installed it previously, and had the same ''DRIVER_IRQL_LESS_THAN_EQUAL'' blue screen, but that stated ''tdk.sys - Address 8AD88B93 base at 8AD81000''.  I am tempted to do another fresh install, and see what happens - but, I suspect I will end up with the blue screen again, with another .sys file :(
    Thursday, January 15, 2009 10:56 AM
  • Does the bluescreen still occur if you uninstall Kaspersky Antivirus?
    Thursday, January 15, 2009 4:01 PM
  • I had clean installed 64 bit beta with no issues (except minor driver compatibilities - to be expected...).

    Then I did an upgrade of my main 32 bit Vista Ultimate system.  The installation upgrade went smoothly, and activation code went in OK.  But every few minutes, I would to get the Blue Screen:

    STOP!  0x000000D1 (0x00000060,0x00000002,0x00000000,0x9343A709)

    KT1.sys (not really "T" - more like a T with the top from the left ending at the vertical bar - not a character on my keyboard), as in    KT1.sys - Address 9343A709 base at 93407000, Datestamp 48849e41

    After turning things on and off, working in safe mode, tweaking BIOS, etc. - I got the idea that it might be my internet security software - Kaspersky 2009 Internet Software.  I tried setting it to Vista compatibility (which has helped a few other apps), but no result (also tried turning Windows defender off). 

    Then I deleted it - and the blue screens stopped.  Not wanting to go unprotected, I installed trial version of AVG interent security 8.0.   Then the blue screens started up again (damn...).  This time, the driver(?)  was tdx.sys, and the address became 906B6B93....

    I uninstalled it, and installed only the AVG free 8.0 Anti-Virus.  Have been blue screen free for 3 hours so far.

    Has anyone else run into security software problems (and are they the cause of just the result of another problem)?

    Friday, January 16, 2009 10:03 PM
  • I was having same exact problem.  My clean install with 64 bit went Ok and used Kaspersky Internet 2009 with no issues (so far).

    But my 32 bit upgrade (of an imaged installation) installed OK, but just like you, every few minutes - down it went with the same K|1.sys....  After uninstalling, it stopped.

    Tried AVG internet 8.0 - same issue - different name   tdx.sys.   Am using AVG free anti Virus ONLY version - no problems so far - been up for 4 hours now.
    Friday, January 16, 2009 10:38 PM
  • That error message is the standard message all Windows Present when they find an IRQ conflict. Ensure your soundcard and video card are not close together on the motherboard which should avoid them sharing an IRQ to avoid future problems.

    Saturday, January 17, 2009 12:50 AM
  • Don't have sound card.

    It turned out to be Virus software - other posters had same exact problem with Kaspersky Internet 2009.
    Saturday, January 17, 2009 2:55 AM
  • Will01 said:

    That error message is the standard message all Windows Present when they find an IRQ conflict. Ensure your soundcard and video card are not close together on the motherboard which should avoid them sharing an IRQ to avoid future problems.

    The text of the error message notwithstanding, every time I've seen this error in practice (including in Vista, not just Windows 7), it's been due to driver issues, not hardware IRQ conflicts.
    Monday, January 19, 2009 2:27 PM
  • I was having the identical problem with an XP installation.   It turned out to be a video card (nVidia GeForce 7600GT) driver issue.  An earlier (not later) driver sorted it.

    I don't know which driver Win 7 loaded for it, but it's been fine so far (several days in).
    Monday, January 19, 2009 5:51 PM
  • Same problem here with 32-bit and Kaspersky and AVG.
      I could even have a stable system up hours at a time as long as I didn't have any heavy network traffic.
    Surfing text pages was fine. as soon as i tried to stream media or copy files - BSoD.

    - The good thing about DOS was - It worked.
    Monday, January 19, 2009 7:46 PM
  • I have the same problem with the tdx.sys when using Avast and Norton 360. I'll try the AVG anti Virus only version, since there seem to have been some successes.
    Sunday, January 25, 2009 11:10 AM
  • I had the same problem with Mcafee 8.7.

    Uninstalled it and the problem goes away.

    Sunday, January 25, 2009 1:35 PM
  • I had this problem with Norton 360, AVG, and avast, always with the problem in tdx.sys. I haven't tried Kpspersky, but am not hopeful when i see how many people had the same problems using it. I am currently without virus protection, because that is the only way I was able to function without blue screen.

    Anybody found an antivirus solution except the above that worked under W7?

    Sunday, January 25, 2009 2:32 PM
  • I had the same problem. Installed the Windows 7 trial and the same thing happend. Renamed Kl1.sys to Ki1a.sys and no BSOd.
    Saturday, January 31, 2009 8:45 PM
  • I uninstalled Kaspersky windows 7 beta, had an Avira premium with a 6 montht free tial, works like a charm, see the link.

    Avira Premium 6 Month Trial
    Sunday, February 01, 2009 1:36 AM
  • Avira Premium free trial for 6 months, works like a charm with Win 7Avira Premium 6 Month Trial
    Sunday, February 01, 2009 1:38 AM