Either you are trying to install something using a Windows user that does not have permission to do so (use the computer's admin account) or your copy of Windows is damaged in some way or another - easiest solution would be to reinstall Windows in that case.
Most runtime errors are unable to be fixed through normal measures. Your quickest route for solving the problem is to simply format. This can be done by inserting your OS Cd and following the instructions that are prompted.
Click Start Menu, Click Run..., Type "Regedit. Click HKEY_LOCAL_MACHINE, Click Software, Click Microsoft, Click Windows, Click CurrentVersion, Click Uninstall and locate the program you want to uninstall, and delete it.
It is a very serious problem. If there is some problem in installation the error will occur. To solve it first go to control panel. Then go to control panel and select add or remove programs and remove from list and uninstall it. Then reinstall the program
The user may not be having administrative privileges. If so, login as administrator and try. Another install program is running on the computer. Press Ctrl Alt Del, click on processes tab, then see if there is any msiexec file is running. If there is anything, right click on that process and "kill" that process.