>>>>>I have run into this before, but haven't really researched it. I am horrible about keeping my Windows XP CD's and I usually keep them as ISO's and burn them to a CD when needed. Sometime a particular key doesn't work with a CD so I try the next CD and it works. Are there different versions or something? I don't think it is the OEM version. I have the regular key on the sticker on the side of the case and it says it's an invalid key.
>>>>
>>>>Yeah, from what I've encountered over the years there are different keys for:
>>>>
>>>>- full version vs. upgrade
>>>>- full packaged product vs. OEM (and probably vs MSDN, academic etc.)
>>>>- XP w/o SP (i.e. "SP0"), SP1 and SP2 (and the soon-to-be-released SP3)
>>>
>>>OEM license keys have OEM in them, don't they? This doesn't - it's a regular key. It's not an upgrade either. It's an IBM desktop and we bought it with XP installed on it, so maybe it IS an OEM license.
>>>
>>>We also bought it before SP2, so that can't be it.
>>
>>It is almost certainly an OEM license if it came pre-installed on an IBM computer.
>>
>>No, the "activation" key that's present on the sticker is a 5x5 character string just like any other. The registration key (more like a registration number, actually) does contain the string "OEM" for OEM installs - this alerts MS support that you don't qualify for free support when you call them. You can view your registration number on the General tab of My Computer...Properties.
>>
>>The activation key and registration number are two different things.
>
>I see. I think that's what I needed. I will need to Torrent an OEM CD version.

So as not to waste your time (and bandwidth :)) make sure you torrent the SP0 or SP1 version as appropriate.