if you can would you go into the bios and tell us what the setting are currently set at and then i'm sure someone can help you step by step set everything up correctly....
shurly they would not put a slower cpu in and try to scam you would they?(they just might....and don't call me "shirlie"

.. )...
but all the info you can give us will help a lot....otherwise we are just guessing......
what "factory"?...like dell or gateway ..ect...
what was the original problem?
what are the specs of your mach.?
remember we can't see what you see(duh...

..)so every little thing may help...tell us what you see!!!