new cpu for my uncle!

[comp builder]

hi my uncle is looking to speed up his computer and i thought maybe replace the processor and up the RAM.
At the moment he has a intel pentium 4 processor, 2.8GHZ (no idea what cache), it's just an HP computer, ready built, about £400 about 2 years ago. He has 512mb RAM
So on a small budget what can he do to speed up his computer, i am going through deleting program's and clearing rubbish off the HDD, and reducing the amount of processes, especially on initial start as when loaded etc it runs at about 27% processor usage

 

[comp builder]

What do you think to this??


processor:

http://www.overclockers.co.uk/showproduct.php?prodid=CP-058-IN




R.A.M-

http://www.overclockers.co.uk/showproduct.php?prodid=MY-081-CR&groupid=701&catid=8&subcat=

 

[comp builder]

with it being an intel pentium 4 i'd imagine it would be 775

what you think?