im honestly not sure it'd be worth it, lga775 was a long time ago. 

according to gigabyte's specs page, the board does not support lga775 xeons, so you'd only be able to upgrade to a different 2core cpu. 

you'd honestly be better off building from scratch, or picking up a an old prebuilt deal on /r/buildapcsales

occasionally you see deals like [this guy](https://www.newegg.com/Product/Product.aspx?Item=N82E16883795872) for 200 bucks, which would be a fairly significant overall upgrade for you

###Build Help/Ready:

Upgrading an old computer to try and get it back in service.

Motherboard: GIGABYTE GA-P35-DS3L P35+ICH9. 
  
Also, comparable RAM and GPU recommendations?  
  
Thanks!

Best processor for LGA 775 socket upgrade for general web browsing, home office, and Photoshop/Lightroom use?