I've been looking through this great forum for a while now (maybe a month) and I understrand perfectly how Vista (SLIC 2.0) and W7 (SLIC 2.1) activation process work... There are beautiful threads on how it all works in the corresponding forums... However, I'm confused when it comes to OEM pre-activation of Windows XP. What are the components needed for a succesful activation? For example, in SLP 2.0 and 2.1, you need 3 components: 1. Slic table in BIOS 2. Cert file (must correspond to the BIOS SLIC table, so brand specific, but any windows edition) 3. OEM key (any of the correct edition of the OS, it isn't brand specific) But how does it works on XP? XP Pro SP3? XP Media Center 2005? All I know so far, is that there is a hidden string in DMI info... But how is it found? Is there only 2 components required? If so, does it means that we need a key corresponding to the hidden string? Are keys version-specific (Pro, Home, MCE, MCE 2005, SP1, SP2, SP3)? Are the strings/key combo working on every edition of XP? Please enlighten me! This stuff interests me! Let's take my situation as an example... I have a old dell laptop with SLP 1.0 in it... But I don't want to use the old given disc (because of bloatware, no Service Pack intergrated makes windows update so long and less clean, etc.) In my situation, I would download a new XP disc with SP3 intergrated... Preferably an original Media Center 2005 SP3 if it exists, with hash to verify authenticity... And then, what else would I need to do? If one day I decide I want XP Pro SP3 instead of MCE, does the exact same process would work?