To work with software like Catia, Solidworks, Solidedge etc. which is the best PC configuration, you will sugest...
most people recommend turning off the 'fancy windows themes (aero)' - it is also great to have a ton of ram.. some of your answer is really application specific.
if you google 'solidworks windows setup' or something similar, you should be able to find a document (from solidworks themselves) recommending various memory settings, scratch disk settings, virtual memory, windows manager, etc. will be good advice for any intensive work on a PC - from video editing to rendering to CAD\etc.
If you have $ to upgrade, consider getting a SSD for your main OS and CAD app... it is a great fairly inexpensive update
PC configurations for Catia, Solidworks, Solidedge
Configuration as follows...If U are wealthy enough,then buy a workstation..if not, then go fr these specs..Intel core i5 or i7 preferably i5 at 3.0 ghz or above...LCD Monitor s available at a cheap price in our country...go for acer or samsung..and fr a CAD software to function perfectly means d reduction of processing time of 3d models ..If U have a good graphics card like ATI radaeon or Nvidia Geforce above 1GB well and good..1TB or 500GB HDD...more than 4GB ram...Ur PC 'd be d best CAD supporting PC...
This is the solidworks document on windows config.. It is entirely appropriate advice for ANY high end computing tasks.