MacBook disk won't verify

I got the following message when trying to verify my disk: "Disk Utility stopped verifying “Macintosh HD” This disk needs to be repaired. Start up your computer with another disk (such as your Mac OS X installation disc), and then use Disk Utility to repair this disk."

(I am trying to honor the hardware-only sticky- so I hope this is the correct forum - please let me know if this is really an OS or software issue)

If I start it with the installation disc will I lose stuff? If I restore it from Time Machine will I also restore the problems?

TIA

Well, first off, I'm guessing if you were trying to verify your disk, that there is something wrong that got you to that point.
That being the case, whether your disk is failing or there is a corrupt directory structure, you have a current time machine backup, and that is your safety net!
This has all the info you need The Repair functions of Disk Utility: what's it all about?
You haven't given any info, but your HD may be on it's way out, and it may not repair. It may die during repair. You may be fine after repairing it.
You would be better off installing Carbon Copy Cloner and creating a bootable clone of your HD as a real safety net.
If the repair fails, I would then boot from the clone (holding option as you boot, and selecting the Clone as the startup disk), erase and zero out the internal HD with disk utility, and then open carbon copy cloner application and clone back from the external HD to the internal HD.