HP Pavilion dv7 won't start?

every time i turn on my laptop it goes to the Starting Windows screen and then the windows logo never shows up and goes into a start up repair. the start up repair is unable to fix anything. i don't have any restore points and i get an error message every time i try to back up my files. i think it's just missing a file to start up but i'm not sure.

this is what the start up repair says:
Problem Event Name: StartupRepairOffline
Problem Signature 01: 6.1.7600.16385
Problem Signature 02: 6.1.7600.16835
Problem Signature 03: unknown
Problem Signature 04: 21200290
Problem Signature 05: AutoFailerover
Problem Signature 06: 17
Problem Signature 07: CorruptRegistry
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 1033

i really want to fix it. any advice?

Needs recovery. The error posted shows corrupted registry! If windows cannot fix itself then recovery is only option.

If this is the original operating system supplied with the hp then tapping f11 straight after turning on will recover back to factory condition! Make sure psu is attachef during!

Performing an HP System Recovery (Windows 7) - HP Customer Care (United States - English) may be of use...

Make sure to backup any important files first. The above will restore the system to factory conditions when it was bought and your programs and data will be wiped clean.