Hello,
There are many aspects of a computer that makes it run slow or fast. We will try to explore them all one by one.
1. Do you have a proper Anti-Virus Program installed?
Many times it is the hidden virus program that eats up your resources and then your machine seems to die. If you do not have one in place, then I suggest you to install Norton or McAfee or any other good Anti Virus program.
2. Are there spyware in your PC?
Check for any spyware in your pc. This may be also one of the main problem which can cause your PC to respond very slowly just because, the main purpose of a spyware program is to transmit that all important data from your computer on the internet. Try installing some free anti spyware like Lavasoft, Windows Defender, etc. You can get these on their website (http://www.lavasoft.com) or (http://www.microsoft.com)
3. Have you installed very high resource consuming programs on your PC?
If you have installed very huge programs that consume a large amount of Processor time and memory then evaluate the situation as to do you really need those programs or not. If you do not require these programs, then uninstall them from your machine, and if you do require those, then you will either have to upgrade your CPU or Memory or Both.
4. Do you regularly clean the Temp Area of your PC?
Make it a practice at least once a week to clear the Temporary Internet Files from your PC. You can do this by going into your Browser Properties and clearing them off... (Different Browsers like Microsoft Internet Explorer, Mozilla Firefox etc., have these options located in different menu places)
5. How often do you analyse your drive for errors and de-fragment them?
Most of your problems might get resolved if you regularly check your drive for errors (weekly recommended) and de-fragment it (monthly recommended). Error removal will cause your processing time to be saved and de-fragmenting your drive will make the files access faster as the whole file will be present at a single place.
I hope you can try with these options and see if it helps.
Cheers.
Saabir.