T710 Windows Server 2008 R2 install

Hi,

My son has recently obtained a T710 Xeon x2 server. It originally shipped with Server 2008 R2 OEM. We acquired the server for his school studies and for his keen interest in networking and hardware in general. As you can guess, the OEM disk is missing and after installing a hard drive, configuring the drive and then installing an OS we have a problem. Initially we installed a non R2 OS in error but it did install fine apart from activation. I understand this will be due to OEM version activation code and the fact it was not 2008 R2.

Our question is. Is it possible to obtain 2008 R2 OEM or can we convert an eval copy from Microsoft to OEM? - I have seen discussions on this also.

Failing this we ware open to any solutions that will allow us to power the server up fully and then start using it and learning more.

Also, the first OS was a 32 bit ver but I think it ought to be 64 bit based on the twin processors? 

Apologies for all the questions, it's a bit deeper than what we are used to but we do have a good PC knowledge in general.

Many thanks in advance