Try downloading the program cacheman and set it to 25% of your memory. Make certain you don't have adware and spyware on your system. Check your computers boot processes to make certain you don't have to many-The number of icons to the lower right of your screen is an indication-over 4 too many.-Im assuming you have moderate memory. If you select start then run, when the window pops up type in msconfig then <enter> Select the far right tab and it will show you what starts at boot-you can selectively turn off what you dont need at boot.-this frees up memory and you should be faster.
When In Doubt-Format and start over