Have you ever seen this message when logging on to a Windows 2008 R2 server? This issue appears often on Citrix XenApp Servers on Windows 2008 R2. If so, there is a relatively simple fix to resolve this.
1) Open regedit on the server
2) Go to to following key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\ProfileList
3) Expand the plus sign to the left of ProfileList
4) Delete any key that ends with .bak