ClockerXP,
" Fark..it didn't work. I set up a copy of my retail CD as OEM cd but the Dell cd-key (from the sticker on the side) is found to be invalid during the install... "
This didn't work for obvious reasons. The Retail CD key will not work with an OEM Version, ever.
Your buddies CD Key will not work as it is an OEM Version and the CD you are using is a Retail version. OK
To be fully legal you couldn't use your CD Key that is attached to the retail version you are attempting to install.
Get an OEM CD and use his OEM CD Key.
or
Get a new Retail License CD Key and use your Retail CD.
or
Get your buddy to cough up the original OEM CD that came with the PC and use the original Key.
These are your options as I see it, ... legally!
pcgeek11