Thanks in advance to anyone who takes the time to reply--but I should tell you that it may be necessary to explain things to me with pictures. (It was my misfortune to major in the humanities.)
1. Make sure video drivers are up to date
http://www.guru3d.com/files_details/amd_catalyst_13_2_download.html
2. Make sure sound drivers are up to date. Guessing you have Realtek
http://www.guru3d.com/files_details/realtek_hd_audio_2_70_audio_driver.html
3. Make sure DirectX is up to date. Run Windows Update
5. Defrag the harddrive
http://www.piriform.com/defraggler
Before you panic and start blaming hardware, always eliminate the possible software issues. Drivers not being up to date or conflicts with windows are the #1 cause of problems. If this is the first time you've heard the word driver and have never updated in 3 years, I'm betting that's the problem.