I was given a PC without a hard disk, that was purportedly lying in a storeroom for 18 months. It has a COA for XP Home (not OEM). I put a hard disk in installed XP Home on it. Before this, I installed linux and run several diagnostics. I had also found the ethernet port to be good and accessed the internet. Then I try to activate XP by internet, it says (after a few seconds) that it can't and I must activate by telephone. What is up? If the key on the COA has been used in the last 120 days, will it give this error?