Run Tune Up Registry Clean Up
Click Optimize and Improve to run Reg Defrag, which will take a few minutes and need a reboot. You should disable the antivirus programme to run this
Check the anti virus is running after the reboot
After the reboot, click optimize then system optimizer to optimize the computer, select computer with an internet connection from the drop down menu, this also requires a reboot
After the reboot, click optimize then system optimizer to accelerate downloads, select the speed just above your actual connection speed, this requires a reboot
After the reboot, click optimize then system optimizer to run system advisor
Try the direct x web installer
Also check Microsoft Update, click optional updates to see if direct x is there