Try this simple steps first.
1. Clean all the junks from your computer by using Disk Cleanup.
Start ---> All Program ----> Accessory ----> System tools -----> Disk Cleanup.
Disk Cleanup ----- > Select C: or whatever drive you installed OS -------> OK ------- >
Check all checkboxes ------> OK.
Clean up your drive(s) at least once a week. Don't delete any log file.
2. Defrag your disk. Make sure you have enough room in your Hard Drive. (At least 50 - 75% Free)
Start ---> All Program ----> Accessory ----> System tools -----> Disk Defragmenter ------>
Select C: -----------> Click Defragment button.
If the above steps aren't help then download a trial version of Tuneup Utility 2007
http://www.tune-up.com/products/tuneup-utilities/ I hope this program can help you clean up all those dead links that slow down your computer.
If nothing solves the problem then try to remove all icons from the right hand taskbar.
Start ---> Run ----> Enter: msconfig ------> OK ----> General tab: Click "Selective Startup". (Be sure everything there checked and select.)
Startup tab: Uncheck all those checkboxes except anti-virus, spyware, and firewall programs -----> Click Apply ------> OK ---------> Close ------> Restart.
Make sure you are not working on anything in your computer. If you do, Save it, before Restart your computer.