looking for advice on upgrading an old dell C521

[faxon]

Okay, so my grandfather really doesnt need a whole lot to do what he wants with his computer, but recently he has become increasingly annoyed at how slow just getting to his email is these days, claiming its a lot slower than it used to be. this isnt surprising, considering he is running vista on an AM2 sempron (1.8ghz) with a gig of ram, and MSN has added some streaming video content to the front page (he's also still on 56k dial up). took me 10 tries dialing before i even got the page to load, an its pegging his CPU at 100% once it loads, even before the video stream buffers enough to run. im going to give him 2gb of spare ram i have when i see him next, but i also have a spare athlon II 250 that i might be able to drop in, however i cant find any info on cpu compatibility for the motherboard other than that it's an AM2 board, and the info on the bios updates mentions nothing about updating cpu compatibility either. the system is a dell C521. combined with getting him a faster net connection, the only way to not make his system chug like a rusty steam engine is upgrading the CPU or getting him a whole new computer. i already have the spare 250 and would like to use it if i can, but i suck at finding dell compatibility information. all i know for sure is were still selling motherboards @ frys using the same 6150LE chipset as his motherboard that are compatible with phenom II x4 chips using the latest bios, but as stated i cant find where dell is hiding this information. anyone here that can point me in the right direction?

 

[cubeless]

the mobo is totally proprietary. as is the case... you can't swap the mobo... i have one sitting right next to me in pieces, the piece of shit... i built a nice new box for the lady who owned it, because trying to fix the thing is a total pita... and this one had an x2 4400 in it, but was still dog slow... i swapped the 4400 for a 3800 in one of my kids' friends pos gateway that i spruced up...

you want a x2 3800 very cheap? pm me...