Question: how to repair windows 7 home basic without cd?
Answer: Try Repairing The Windows 7 Installation.
1a. ... 
﻿1b. ... 
Choose your language and click Next.
Click Repair Your Computer and then select the operating system you want to repair.
Click on the Startup Repair link from list of recovery tools in System Recovery Options.
More info and a how to guide:
If that doesn't fix it: