Error 1935 on install, fixes dont work.

I am installing Adobe Acrobat 9 Pro on my Windows 7 computer, and getting error 1935 repeatedly.  I have tried the suggested fixes:  re-downloading the program and re-installing; clearing the transaction log; disabling virus scanner; and looking for any spyware that might need deleting.  None of that worked.  Any other suggestions to try?  Thank you in advance for your time.  -Kim