Hi cherisarno, I had same problem in Windows 7. Here's a couple of things to check.
1. Make sure you are using the Administrator account. You can find detailed instructions on checking and adjusting this here: http://goo.gl/L7sHB
2. The User Account Control (UAC) may be turned off. Detailed instructions are available here. Windows Vista: http://windows.microsoft.com/en-AU/windows-vista/Turn-User-Account-Control-on-or-off
Windows 7/Windows 8: http://support.microsoft.com/kb/975787
3. Try turning of all security software before trying to install. REMEMBER to turn it back on after install.
good luck
Steve