Right-click on CMD and click Run as Administrator.

There are times when you may encounter sudden application lags and freezes, or even system crashes, making it inconvenient to use your computer. The issue could probably be a file or application error in the Windows 7 system. The usual fix for this is restarting the computer, but here’s another way to fix file errors.

1. Open the command prompt, also called a DOS Box. To do this, click Start. Type CMD in the box and press Enter.

A new window will appear.

2. Or, click Start, then All Programs, then Accessories, then Command Prompt.

You may not be able to run commands in the Command Prompt unless you run it with administrator privileges. To do this, right-click on Command Prompt or CMD instead and click Run as Administrator. You may need to enter a password.

3. In the command prompt window, type “sfc/scannow” (without quotes). The Windows 7 system will automatically verify all files and repair any existing files that are corrupted.

This system scan will take some time.