Hi! It is important to know your system information in order to know what is the probable cause of your issue. However, to identify the issue, please ensure that you have run the following:
1. Run your antivirus and scan your whole system so we can be able to know if your system has been attacked by some virus or any malicious scripts.
2. You can also run a Desktop Cleanup. To do this:
a. Click Start and then open Control Panel.
b. Click Appearance and Themes under Pick a Category in Control Panel.
c. Click Display on the pick a Control Panel icon.
d. Click the Desktop tab and then customize desktop in the Display Properties dialog box.
e. When the Desktop Items dialog box opens, click to clear the Run Desktop Cleanup Wizard in the Desktop Cleanup box. (you can select if you wish to run the
wizard automatically every 60 days)
f. Click Clean Desktop Now.
3. Defragment your local disk. Just open My Computer and then right-click the drive that you want to defragment, then click Properties. Under the Tools tab, click
Defragment Now and then Defragment.
4. Delete unwanted files or folders to free some space in your system's memory.
5. Run the system restore.
6. Insert your Windows XP Recovery disk and run it.
7. If none of the above works, you can also reformat your system if you have a Windows XP installation disk.
To know more about how you can resolve this, I found a similar issue in this site: http://www.techyv.com/questions/why-my-pc-has-become-so-much-slow you can check on it and maybe you can find some useful tips to resolve this.
