If your PC is 7 years old then my guess is the RAM will be DDR2 and not DDR3 so wont fit your present motherboard.

Also,the hard drive and DVD-RW drive will be PATA interface and not the newer SATA so also wont be able to fit.

I go with ditching the lot and buying all new,I always even buy a new case for my new builds to freshen up the look.

A decent brand of PSU is very important as already stated.

Go with at least 4gb RAM,cheap nowdays.

An Intel Pentium G-3250 @ 3.2Ghz has graphics onboard so no need to buy a graphics card unless you render HD video or play games.

I can highly recommend the list from invadeit but then you must build yourself.

Good luck !

4 GB DDR 3 under 1000 baht at Advice shops.

OP might be interested to have a look at the magazine 'Linux Format' (Aug 2015). Available via usual www. sources. There is an article concerning constructing a linux PC which of course is relevant to a dozer PC. AA