You can use the resolution menu in Windows 7 to rotate your screen. In order to access this menu, simply right click on your desktop and open screen resolution. Click on the orientation tab and you will see the different options available. Select the drop-down menu and check the orientation which you want to keep. Click okay and you will see how your desktop will turn just the way you want it.
You can also use your video card’s control panel. Access it by right clicking on your desktop. The rotate option is on the left hand side of the control panel. Once you have selected the angle at which you want the screen to tilt, click apply and close the window.
The iRotate software is also a solution to this specific problem. You can simply download the software and can see how it gives you the option to rotate your screen at any angle you want. You can either choose from the four angles provided to you (0, 90, 280, 270), or you can add an angle yourself on the space provided to you right in the bottom corner. After you have decided on the angle, simply click apply to check whether you have flipped the screen perfectly or not.
The last option is an in-built feature which comes with all Microsoft Windows. Click Ctrl + Alt and play with the arrow keys. If you press the up button with these two keys, the screen will remain in its place. If you press the right button, it will tilt at 90 degrees. With the down button it will tilt 180 degrees and with the left button it will tilt 270 degrees.