Beta testers of Windows 7 report that recently released security updates pushed through the Windows Update mechanism cause blue screens of death (BSOD) at startup, with a failure on kl1.sys.
It appears that, in some cases, this problem may be caused by a conflict with the Kaspersky Antivirus package. Follow these steps to disable the software:
- Startup in safe mode (tap the F8 key on your keyboard repeatedly as the computer is starting up)
- Select a method of safe booting from the menu (first try with networking; if the crash still occurs, try without networking)
- Once the system has booted, click the Start button and type MSCONFIG then press enter in Windows Vista (in Windows XP, click the Start button, then click “Run” and type MSCONFIG then press enter)
- Go to the startup tab
- Disable Kaspersky and any related items (e.g. kl1.sys), then press OK, then restart the system if it does not happen automatically. Startup normally (i.e. not in safe mode)
Alternatively, you can launch the Kaspersky application and set it to not start at startup.
If you wish to continue using Kaspersky, you can try installing the technical preview for Windows 7, although it may exhibit similar issues.