Suggestions for computer upgrades?

alright as far as increasing the speed goes i would definitely get rid of that Pentium D and start looking into a quad-core(http://www.newegg.com/Product/Product.aspx?Item=N82E16819115057) that's the url for the quad i bought for my computer a while back. adding more ram will help but it might not help as much as you think, you should really only need at most 3GB uming your running windows xp or vista. if i were you i would look into a second hard drive to store music or anything on and i would save that 250 GB you've got for system files and program files only, stay on top of basic maintenance ( defrag and other such resources) and that should help you out a little bit. if not you might want to look into basically rebuilding your pc or buying a new one (if you decide to buy new parts for the computer instead of buying a whole new pc then i suggest getting the parts off of newegg.com they've always been good when Ive ordered from them and they should have just about any part you would want or need) hope that helps you out