My windows defender won't start. I cannot delete, install or repair it from the install .msi file. It says that defender is not installed when I try to repair, when I try to delete it reports that this action is only valid for products that are currently installed and when I try to install it states that this product is included with vista. I can't win on this! Any help would be appreciated.

Hi, Do these 1st : Run DiskCleanup - Start - All Programs - Accessories - System Tools - Disk Cleanup Start - type in Search box - COMMAND find at top of list - RIGHT CLICK - RUN AS ADMIN sfc /scannow How to analyze the log file entries that the Microsoft Windows Resource Checker (SFC.exe) program generates in Windows Vista cbs.log http://support.microsoft.com/kb/928228 Then run checkdisk - schedule it to run at next start and then Apply OK your way out then restart. How to Run Check Disk at Startup in Vista http://www.vistax64.com/tutorials/67612-check-disk-chkdsk.html ------------------------------------------------ Troubleshooting Windows Defender http://support.microsoft.com/kb/555957 "%ProgramFiles%\Windows Defender\MsAsCui.exe" is the default Defender folder Start - type in Search box -> Windows Defender - find at top of list - Right Click on it - RUN AS ADMIN If no joy use Start - Computer or Windows Explorer to navigate to that folder and create a Shortcut to put on Desktop and Start Menu. You can also Right Click any exist shortcuts and see if they point to there. Target "%ProgramFiles%\Windows Defender\MsAsCui.exe" Start In "%ProgramFiles%\Windows Defender" How to Turn Windows Defender On or Off http://www.vistax64.com/tutorials/93118-windows-defender-off.html -------------------------------------- Maybe something here if needed : What is showing/causing the error message? Some security/anitvirus/antispyware products can cause this error. Which of those do you use INCLUDING any that your ever had even those uninstalled (the remnants can cause issues). McAfee is just an example of what many can do. Start - type in Search box - Services - find at top of list - Right Click - Run as Admin Windows Defender - set to STARTED and AUTOMATIC or set to STOPPED and MANUAL if needed Fix for the 800106ba problem. http://support.microsoft.com/kb/931849 McAfee error report http://service.mcafee.com/faqdocument.aspx?id=TS100610&lang=en_US&prior_tid=2&AnswerID=16777216&turl==http://kb.mcafee.com/infocenter/index?page%3Dcontent%26id%3DTS100610%26actp%3Dsearch Also check : http://social.answers.microsoft.com/Forums/en-US/vistasecurity/thread/574fb871-034c-4b42-b800-328af16a9177 Hope this helps. Rob Brown - Microsoft MVP <- profile - Windows Expert - Consumer : Bicycle - Mark Twain said it right.