It would help us to know which model computer you have, which OS version you're using, how much RAM (if applicable), etc. You can have this info displayed on the bottom of every post by completing your system profile and filling in the information asked for.
This will help in providing you with the correct troubleshooting solutions. The more info about your computer you include, the easier it is to help you.
Please describe in detail all you have attempted to do in order to resolve the issue.