I have no idea what happened, but suddenly I cannot execute any programs at all on my XP box. Trying to run anything results in the error message:
Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.
I cannot run items in the control panel, and I cannot run "cmd" to get to the command line.
As well, many programs are missing from the Start Menu and Start Up programs are not launching.
This occurs for all user accounts, including administrative accounts.
The exact same issue even occurs in Safe Mode.
I am running Windows XP SP3.
Any help would be greatly appreciated as I am completely Googled out at this point.