I have Vista Business running under an admin user account, and I can't initiate a Remote Assistance session by going to "Help and Support". In the Help and Support center, I click on the link "Use Remote Assistance" and nothing happens. I have turned on RA by going to System, Remote Setting, Allow Remote ....; checked the Firewall; etc. When I try to start RA by running msra.exe, I get an error message "Windows cannot find C:\Windows\System32\msra.exe, even though I can locate this file in the System32 folder. I have run "SFC /scannow" and everything appears OK. I also have this problem with "On Screen Keyboard" (osk.exe, same symptoms), but everything else in Vista appears to be working fine. Any suggestions would be appreciated.