Reading through this thread again I noticed you have a laptop.
i have a pre built model from Dell, the model is a Dell latitude D520 if that helps thankyou ;D
I looked up the specifications and your laptop and basically they are.
Intel Celeron m cpu 430 @ 1.73GHz
504 MB of DDR2 RAM (system memory)
IntelĀ® Graphics Media Accelerator 950 (Up to 128MB shared with 256MB system memory or up to 224MB shared with 512MB system memory)
40, 60, 80 or 100GB Hard Drive
http://www.dell.com/downloads/emea/products/latit/Lat_SpecSheet_D520_Final.pdfYou RAM (system memory) may be 512 MB with 8 MB used for video. You posted 504 MB but they way I told you to find out how much ram you have the number shown would have already subtracted the RAM which is taken by the graphics card.
I don't know how big your hard drive is or if it is full or not. If you hard drive is less than 15% free then windows can be slow at doing things.