Thanks, I'd never have guessed it was that. I had just been tweaking all the start up stuff for several local users and at the first switch to a different user ... bang! goes anvshell. I was sure it must have been due to my startup tweaks ... but then I found your post and I realised I'd also moved everyone's My Documents folder to another drive. Putting them back fixed it alright, but I experimented a bit anyway: actually there's no problem while the folder is anywhere under the Documents and Settings folder. Perhaps even anywhere on the %SystemDrive% but I didn't try that. Others drives though are a problem. BTW I've also seen that it's up there in MS's KB (Since August!!!). Cheers