Supporting Windows

I have problems with the vss.  When I ran vssadmin list writers there were no list.  Several months ago, I research on the internet and suggest I Delete the HKLM\Software\Microsoft\EventSystem\{26c409cc-ae86-11d1-b616-00805fc79216}\Subscriptions key.  It works for 2 months and the problem re-service again.  I want to install kb940349 because I do not have backup of this server for about 1 week now and I show somone said they can't restart server after they install this patch.  Can we uninstall this patch anyone has good idea of best way to fix the vss problem.