Sophos Anti-Virus custom action install log, located in the folder C:\Windows\Temp\, shows the following error...
Known to apply to the following Sophos product(s) and version(s)
Failed to grab execution mutex. System error 258.
Sophos Anti-Virus for Windows 2000+
This error can been seen due to one to the following reasons:
- Msiexec.exe process is already running on the machine
- The registry string PendingFileRenameOperations is currently populated and the computer is waiting to be restarted.
What to do
Open the Windows task manager and kill any remaining msiexec.exe processes running. Attempt the install again.
If the error remains reboot the computer and run the Setup.exe file again.
A further reboot, after installation, may also be required.