cyclic redundancy check, unmountable boot volume?

Alright so I've had my computer for right over a year. Never experienced any problems. However, yesterday my toddler got ahold of my laptop for 15 minutes, i came back and he had locked the desktop and several files were opened when i typed my password and got back in. The computer was running slow so I restarted, when I restarted it would not load. When i got home i decided to reformat the whole thing. The reformat went fine until it was over and the computer restarted. It kept going in a loop. I could see there was a blue screen but before i could read it, it would dismiss it and restart all over. So i disabled the computer from crashing and restarting after the error so I could read the blue screen. The blue screen read Unmountable boot Volume. I found my system repair disk and inserted it. The Bios is showing the HD, but when i try to access it from my command prompt in my startup repair, it says Cyclic redundancy check. I do not have the windows 7 installation disk and have always reformatted from the system repair. I'm starting to believe my HD is fried, but I found it a little difficult to believe since he was only alone with it for 15 minutes and the computer has never shown any signs of HD failure ever. Any tips, advice, or anything?

It's a Toshiba Satellite L655-S5150.

Thank's in advance.

Is the HD detected when you boot into BIOS setup? If not check the HD is making firm contact by reinstalling it. If that fails replace it.

If HD is detected or once it's replaced follow these steps to get a perfect Clean Reinstall - Factory OEM Windows 7. Everything needed is provided.

If there's further problems run the hardware tests in Troubleshooting Windows 7 Failure to Start

Thank you for the response. I finally got my OS disk to work. There is currently no OS listed. The HDD is showing up with only 20 gigs missing from the 250g HD, when i went to delete the partitions i received an error, when i tried to just install i received a separate error. So without being able to install the OS, Delete the Partition, or anything of the sort, what option am I left with?

Test the HD with the maker's HD Diagnostic extended CD scan, followed by a full Disk Check on a full disk partition. This will tell with certainty the condition of the HD.

If you need to make a partition use free Partition Wizard to Partition Wizard Create Partition - Video Help
then run Partition Wizard Check File System and Partition Wizard Partition surface test