While attempting to add Disk Cleanup to Scheduled Tasks I ran cleanmgr.exe /? in a command window to find out the available switches. Two of these undocmented switches /SETUP or /TUNEUP:n ran without feedback. When I returned to the desktop my Quicklaunch bar was empty and no programs would run. What folders remaining in Program Files contained no executables. A search of Microsoft and Googling the internet failed to turn up any reference to these switches. I also searched a number of Vista books (pdf format) without any luck. Fortunately I always make a full Acronis backup prior to Update Tuesday and was back up and running very quickly. Just had to redownload the recent updates. The /Sageset:n and /Sagerun:n worked and I was able to schedule Disk Cleanup. System is Vista Ultimate x64 SP1. Any information would be appreciated.