So basically I just installed my FX-4130 with 8GB ram, and I need to get a 64-bit OS. I read through some sites etc. and seems like you must boot your computer with an OS DVD in order to turn 32-bit into 64-bit. So my question is, can I boot up an upgrade DVD or do I need an OEM one? Also do most places that sell OS's have OEM's too? Windows 8 upgrade costs only 59€ now, normally 270€ so I'd get that if I can turn my computer into 64-bit with that.
No, you cannot upgrade from 32-bit to 64-bit. You need a fresh (clean) install. But I'm just referring to the installation method (not the licensing), I think you can still save money and just buy the upgrade DVD to Windows 8 64-bit.
In other words, from a legal standpoint, I think you can buy the upgrade license to Windows 8 64-bit from Vista 32-bit (I think you can even upgrade from XP 32-bit). With an "upgrade" CD you still have the option to do a clean install (I think). Just back up all your files on a external drive and do a full install (reformat) and you should be fine. But you can check with your vendor he might provide more information.
if you have a version of win7 (does not need to be activated)... you can install win8 using the upgrade version.
(install win7... just click the "entrer key "
TL;DR... install any supported version of windows... then delete the previous win install using the advanced/other opitions tab in the win8 install... then go back to the win8 "clean install" option and install win8... done, and no need for the non-upgrade version of win8...
BUT, if you get the "full" or oem version of win8, it has downgrade or the key that can be used for a win7 install.