It seems that Windows 7 is a really stable operating system and you might never have to use the system repair disk, but it is always good to have one in case you are unable to boot-up your computer; the system repair disk contains Windows Recovery Environment, which has all the necessary tools that will allow you to successfully boot-up.

Creating the disk is pretty easy and straightforward:

Click the Start button, type recdisc.exe in the search box and press Enter. Select the drive, where you have inserted the blank CD or DVD from the drop-down menu and click Create disk.

Once created, you can use the Windows 7 repair disk in case your system malfunctions and you cannot boot-up; simply select your CD or DVD drive as the first boot device in your BIOS, insert the recovery disk, and restart your computer. You will be presented with the following recovery options: Startup Repair, System Restore, System Image recovery, Windows memory diagnostic and Command prompt.