Can you give us the exact error message that you are receiving? What OS and browser are you trying to install Flash Player on?
"The user does not have sufficient privileges to install Adobe Flash Player"
I have windows and internet explorer...but I'm not sure what version. Sorry
Can you try to do a clean install
When doing this, please make sure that all files have been deleted in your \macromedia\flash folder (either in c:\windows\system32 or c:\windows\syswow64 folders).
If you continue to have problems, please post back with your flashinstall.log file.