If using a user other than the one that installed the Performance Analysis GUI, it will not connect and shows the error message "Unable to initialize Performance Analysis." If you click on Details, it says "Division by zero". The user has full administrative privileges on the client machine.
Corrupted profile files.
The profile files may be corrupted. Exit performance analysis, delete the profile files found under C:\Users\<user>\AppData\Local\Quest Software\Performance Analysis MSSQL 6.0\Services directory. Then launch PA again, create a new profile and try connecting again as the alternate user.
Note: "username" in the above path would be the original user.