I recently upgraded my WinXP Pro SP2 PC from SQL Server 2000 to SQL Server 2005. After a subsequent reboot and login, I saw a generic error message:
Error The system cannot find the file specified. OK
I didn't think much of it the first time, but it appears each time I reboot.
Sysinternals' Process Explorer identified the error dialog with C:\Program Files\Microsoft SQL Server\80\Tools\Binn\sqlmangr.exe. I just realized today that upon pressing the OK button, SQL Server Service Manager appears in my system tray, with a solid white circle. Upon opening Service Manager, the Services list is empty. The status bar says it is "Not Connected". I figured the entire ..\80 directory had been removed as part of the 2000-to-2005 upgrade; however, the directory and .exe do exist. Is this normal?
I think your problem was caused by the SQL 2000 install. I had an old Beta 2 copy of SQL 2000 on my development system, which had long since expired, and I ran into the same problem trying to install SQL 2005 Express. I suspect you have found a solution by now, but in case someone else runs into the same problem just uninstall SQL 2005, uninstall SQL 2000 and then install SQL 2005.
I had to uninstall SQL 2000 manually by following the instructions at the following link.