Here is handy commands to check and repair current windows systems such as Vista, win7 and so on.
From command prompt :
Step 1. Click Start and then type cmd in the Start Search box.
Step 2. From the searching, you will see cmd icon in left side top.
Step 3. Click right button to choose Run as administrator
Step 4. From command prompt, typesfc /scannow
Once the scan is completed, you could see below output.
In this case, no issue was discovered. If an issue is identified, it will give you option about system restore and recovery from saved restoring points.