Windows 7: Re-installing 2 OSs

Hey folks, i've got a bit of a dilema.
Here it is.
I've got a computer i made my self, my dad bought the family pack thing of Win 7, so i installed of course, it's in english, thing is, it was getting a bit sluggish and i finaly decided to buy a laptop, from ebay france (b'cos i live in france), it's an Acer and the os is Win 7 home prem, but in french, i don't have a problem with it being in french, but i'm wanting to sell my old one, with Win 7 in english, that is going to be difficult, so i'm wanting to know if it is possible to a swap or something.
I rang microsoft asking if i could do a license swap (legally), which is a no go, as you would expect b'cos the new one is OEM, so has anybody got any ideas? (doesn't have to be legal).
In other words i just want to put a french Win 7 over my English one and Vice Versa

Thank you

Since the French version is OEM you can't move it to any other hardware. And the licenses are language-specific on all versions except Ultimate which includes Language packs.

The family pack retail version can be installed over the OEM to have English version on your new laptop. You can even try to do an in-place Upgrade install from desktop which saves your programs, files and settings. It may allow it as a same-version Repair Install. Afterwards you would install the key at Control Panel>Properties link.

ok, yeah i though about that but just means i won't have a version on my old, i think ill just stick with the french one, thanks any way