Unless you are an avid gamer you will notice little or no change. The difference between Igb of DDR 333 RAM and 1gb of DDR 266 will be equally negligible as will the difference between a 1700 and 3000 processor. Even if you are well into games the system will be only as good as the worst part...so the graphics card willl need to be changed ;-)) If you require extra speed you will be better off buying an external HD and dumping everything that you rarely use on there, hitting start-run- and type msconfig and turn off everything that is not needed apart from your firewall, AV, explorer and systray.
... the pc runs fine most of the time. The only thing is that programs have begun to open a more slowly than before as i have alot of applications open. When i cherck the system performance i can see that alot of memory is being used. 350 mb plus.
I dont want to spend to much money as i will be doing a full upgrade in a year. I was thinking that spending 100 quid might do the trick on extra memory and a slighlty faster cpu.
You have too many programmes running in the background...msconfig and go to start up...untick everything that is not needed to run in the background (Real player, office etc,) Buying an external HD is a good option.