ok, lets take a breath here everyone, some of your suggestions are correct, but reasonings wrong. MacAfee is probablyu the issue.
Now here is why:
You did not turn it off when installing Shockwave. MacAfee and Norton both consider ANY program to be hostile and they really mess with installs. MacAfee/Norton is also about the weakest virus protection you could have on your computer besides having nothing. Top that off with the fact that MacAfee uses a minimum of 20% of your system resources, and you might as well just use your PC to keep paper from flying away.
Step 1:
REMOVE MACAFEE/NORTON - I cannot stress this enough, Macafee/Norton is the worst possible virus and security software on the market to date. They have been causing problems since Windows 3.1
Step 2: Install new, free, virus program: Try Avast! you will love it - find it on download.com
Step 3: Remove shockwave and flash
Step 4: Run a thorough scandisk and then defrag
Step 5: get a can of compressed air, open your PC and blow out all the dust inside (you will be surprised and might want to wear a dust mask)
Step 6: Reinstall Shockwave and Flash
Step 7: let us know if it works.