If the combined time for startup or logon (and logoff or shutdown) script processing exceeds the systems 10 minute default, the script processing aborts and records and event error.

You can alter the time limit using the the Maximum wait time for Group Policy scripts Group Policy at Computer Configuration\Administrative Templates\System\Logon or User Configuration\Administrative Templates\System\Logon.

If the policy is Not defined, you can set the MaxGPOScriptWait value name, a REG_DWORD data type, at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System or HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System.

A data value of 0 causes the script to run to completion, without regard for time. You can set the data value to the number of seconds desired, between 1 and 32000 seconds.

NOTE: An entry at HKEY_LOCAL_MACHINE takes precedence over a user entry.

NOTE: See RunLogonScriptSync.