It sounds like the hardware is OK.
One option is a free operating system - like Linux.
If you want to test it out first.... you can download and burn a bootable CD or USB thumb drive.
It's not 'windows' but it's also not so different you can't figure it out with some of the help guides out there. Ubuntu Desktop
It's fully worth your time bugging your friend for the missing license key.
Other options - (that still have a problem with missing license key for activation):
Borrow a friends Win7 installation media.
Download and burn your own install media. example