mmm by searching on the subject i have to say i hate Microsoft with this idiotic monopoly on laptops and this bullshit with OEM keys. It actually means that you cant even upgrade your pc from what i am reading right now!
I also found out that there are branded keys. For example the XP Home Edition ULCPC for my s10-2 lenovo doesnt state anywhere OEM but only Lenovo. Does this means it can be used on Lenovo products maybe?
The 7 Home Pre OA for my Dell indeed seems to be OEM since it writes OA....
Anyway...Thanks for replies everyone