Open a DOS console and type "set" - you should see all your environment variables.

It's present in Win XP, I don't have a 2K box to hand to check.

If the delete fails it will do so silently. To check the status, use the @ERROR macro.

After you delete command, add the following line:
Code:
"Delete status was "+@ERROR+": "+@SERROR+@CRLF


This should give you a "0" status (which is success), or a value which indicates what the error was.