Performance Information and Tools lists your computer’s Windows Experience Index base score, which indicates the performance and overall capability of your computer’s hardware.
You can go to Control Panel ,then click Performance Information and Tools to rate your windows 7 system.
Now in the new windows,you can click “Rate this computer” to test your PC’s performance.After that you can see your PC’s score about this testing.
From the above image we can find the rating give us a base score of our PC ,also separately test the performance of:
Primary hard disk
Tips:You can click Advanced Tools ,then click Clear all Windows Experience Index scores and re-rate the system to re-rating your windows 7.