Today when I tried to run an old DOS utility from the XP Command prompt, I got the message "Access is Denied." Then I found that most of the DOS utilities would not run, even though I have "full control" over them. They worked just fine a few weeks ago, and I have not made any OS changes other than Windows Upgrades.

Then I tried running edlin.exe and edit.com from the Windows\system32 folder. Same result - "Access is Denied." I tried running these applications from Windows Explorer and got the message "Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item."

I am logged in as a member of Administrators and have full control over these files. I tried logging in as THE Administrator, with no change. I checked the security settings on the files, and have full control over all of them. I have tried copying the files to different drives, booting in safe mode, and running without antivirus and firewall, all with no change.

Does anybody know what could cause this?