You can trying using this batch file :
:: Set the varibles - Use Quotes "" if there are spaces in the source or log path
:: Find Encrypted Files
cipher /s C:\ | findstr "^.E" >> %log_path%\found.txt && echo:Encrypted files found"
:: Find Hidden Files
attrib /s C:\ 2>nul | findstr "^....H" >> %log_path%\found.txt && echo:Hidden files found"
This batch file will scan your C:\ drive for all EFS encrypted files (and also hidden files), echo on the screen every time it finds one, and record all instances of encrypted files found into C:\EFS_Find\found.txt.
For a command-line approach to finding just encrypted files, you can type in the command-line :
cipher /s:C:\ | findstr "^.E" >> C:\efs_found.txt && echo:Encrypted files found"
This will search your entire C:\ drive for encrypted files, and dump it into C:\efs_found.txt.
Modified from the solution found here.
To disable EFS on your Vista system, I refer you to the link here :
How to Disable or Enabled EFS Encryption in Vista