Rename the directory where the profile is stored.
Open regedit.exe, find HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList, and delete the key showing your profile’s SID (you can use the ProfileImagePath value to help you determine which one it is).
Log off and then log on again.
Mitch Tulloch was lead author for the Windows Vista Resource Kit from Microsoft Press, which is the book for IT pros who want to deploy, maintain and support Windows Vista in mid- and large-sized network environments. Mitch was also the author of Introducing Windows Server 2008 and technical project lead for the Microsoft Office Communications Server 2007 Resource Kit, both books also from Microsoft Press. For more information on these and other books by Mitch, see www.mtit.com.