This article explains how to create a Windows 7 System Repair Disc. This will give you access to System Recovery Options, a powerful suite of Microsoft-created diagnostic and repair tools such as Startup Repair, System Restore, System Image Recovery, Windows Memory Diagnostic, and Command Prompt.

You will need an optical drive that supports burning discs (you probably have one; this is very common) to create the disc. Unfortunately, a flash drive is not a supported bootable medium in this case.

This whole process is very simple and only takes about 5 minutes:

Insert a blank disc into the optical drive.