This happens to a Compaq workstation. If installed with Norton Anti Virus 2002 or Grisoft Anti Virus, once the AUTOEXEC.BAT completes its execution Windows will crash - no blue screen of death; just a black screen with a blinking cursor. Upon uninstalling of these anti virus programmes (only one installed and uninstalled at a time), Windows have no problem in starting. There's no virus infection - I have used AVG rescue disk to scan through the system. However, after I installed AntiVir Personal Edition (from H+BEDV URL: www.free-av.com), Windows starts up without any hassle and this anti virus works. I read somewhere in AntiVir's site that on certain machines other anti virus programmes may cause system crash due to UMA issue (not sure what is meant by this). Can anyone help me out here in the sense that I prefer to use either NAV or AVG where updates are simple to fix whereas in AntiVir, one has to download the entire new installation file in order to keep AntiVir updated. Thanks.

When you uninstall AVG and then reinstall it, are you using the same download? Have you tried a new download from the Grisoft website? Do you use the search function to see what remaining files might still be in the system, and delete them? Have you checked the registy using regedit for any remaining program files?

Hiya Capt, The AVG I used was one which has been downloaded from AVG's site and not sourced from third party. Additionally the installation copy worked flawlessly with other PCs. I believe the problem is not so much as to corrupted installers but UMA (if only I know what that is and how to resolve that problem!!).