Well it might be late but if u hasn't solved it yet here is what I did.
I found below Guideline somewhere
• Create a folder name "Temp" under C:\ [This step is important, the folder has to exist.]
• Right click the Computer in Start menu and select Properties
• Click Advanced System Setting
• In System Properties windows, click Advanced tab
• Click Environment Variables button
• Under User variables list, double click TMP
• Change Variable value: from "%USERPROFILE%\AppData\Local\Temp" to "C:\Temp"
• Try to install the program
I did as above Guideline but didn't work. Then I tried this
1. Right click on a file
2. Click "Run as Administrator"
And it worked!
That simple it is!