Itunes was updated on my windows computer and now itunes will not work

While downloading an update of itunes, I rec'd an error message that it was not installed successfully. Now if I try to start itunes I get a message "APSDaemon.exe system error Program connot start because MSVCR80.dll is missing. Try reinstalling the program to fix the problem.

I have uninstalled and reinstalled the program 4 times with no success. I tried doing a "repair install" with no success. Another error message I rec. is Apple Mobil Device failed to start. Verify that you have sufficient privileges to start system services.

I am the owner of this computer and I have been using itunes with my ipad and iphone for several years with no problem on the upgrades.

Please help this is very frustrating and time consuming . I have run McAfee full scan and ther are no issues.