Windows 7: Can I use a new OEM license key to Upgrade after new motherboard?

Hello, I would like to know if I can purchase a Windows 7 oem activation key and use it to activate my existing Windows install. I just replaced my motherboard and have an OEM license. My old computer was an eMachines and they don't have a phone number for windows support. I was just wondering if I could just purchase the key and upgrade it like that. Thank you for your time.

I would first try to get it activated with your old key. Yes, in principle you cannot move an OEM key from one mobo to another. But if you have a good story, MS may let you get away with it. The numbers to call are here: How to contact a Microsoft Product Activation Center by phone

And yes, if you buy a new key, that should work. But why waste the money. Maybe you are lucky.

The only thing is, it doesn't come up with an option to call microsoft. Just eMachines... I think i might need to buy a new key... and one more thing, if i buy the key will i have to clean install it? Or will it just activate for me?

Did you look at the link I posted ??

faillord click on the link WHS provided in the color blue, it will give you instructions on how to get a hold of Microsoft to discuss your problem and negotiate about the oem key

From the sound of it, you are currently using the OEM_SLP Key for windows.
First try changing the Key to teh one on your COS sticker using the following method

Click on the Start button
in the Search box, type
SLUI 3
and hit the Enter key
The Change Product Key wizard should come up.
Change the Key to the one on your COA Sticker on the machine, and follow the instructions - you may still have to activate by phone, but depending on whether the Key has ever been previously activated, you may not need to tell the operator anything.

You may need to activate by telephone.
If you are not offered the option, then use the same method as above, but with
SLUI 4
follow the instructions - but when asked which service you require by the telephone ansafone, do NOT reply - this should force an operator to respond, who can deal with you.