Make sure you have local admin rights and UAC disabled before downloading and installing. And definitely use the Virtual Agent as suggested above. If you still run into issues, then you might need to manually change some permissions on some folders.
How to add the Everyone group with Full Control permissions to the Config.Msi Folder
1. Click the Start button or press the Windows button on the keyboard.
2. In the Start Search box type %temp% and then click the Temp folder item that appears at the top. (Win + R also gets Run box)
3. At the top of the Explorer window, in the address bar, click the folder to the left of Temp in the folder path (Local by default).
4. In the folder list, right-click the Temp folder and then click Properties and then click the Security tab.
5. Click the Edit... button and on the next screen click Add.
6. On the next screen, in the large text window type Everyone and then click Check Names - Everyone should then be underlined.
7. Check the box for Full control under the Allow column, and then click OK, then OK again, and OK again to close all the windows.
8. Do the same for the C:\Config.msi folder if it exists.
If all else failes, move the %TEMP% folder from your user profile to a new folder on C:\ called C:\TEMP. If you get to that point and still need help, let me know.
Good Luck!