First make sure that XP SP3 is totally up to date with all updates, including IE8.
(McAfee uses IE regardless of your default browser selection).
That directory is probably inactive so best uninstall McAfee first via Control Panel if listed.
Then run the MCPR cleanup tool. Reboot
(Run twice if it reports an incomplete removal)
Got to your online account page and download a new installation.
If for any reason the account says no license available, contact Customer Service to explain what happened and they should be able to free one up to for you assuming you have more than one allowed normally.
Customer Service is linked under Useful Links at the top of this page and it's free of charge by phone or online chat.
many thanks for the instructions. Worked perfectly, although I had to phone Cust. Services to reset for the new name given to the computer after the reinstallation of Windows, but agian this worked smoothly.
That's good and yes, they can usually sort out those sorts of problems.