windows vista does not boot

my lenovo ideapad y450 does not boot. windows vista home premium 32-bit. the loading screen infinitely loads but does not enter the log-in screen. i just force shut down when that happens by holding the power button. then after 2 or 3 times of that,

this came out..
.............................................
windows Error Recovery
windows failed to start. a recent hardware or software change might be the cause. to fix the problem:

1.insert you windows installation disc and restart your computer.
2. choose your language settings, and then click next
3. click "repair your computer"

other options:
safe mode
safe mode with networking
safe mode with command prompt
last known good config
start windows normally
.............................................

i decide to enter safe mode then this comes out and loads (but it stops in loaded: \windows\system32\drivers\crcdisk.sys)

loading windows file
.
.
.
loaded: \windows\system32\drivers\disk.sys
loaded: \windows\system32\drivers\CLASSPNP.sys
loaded: \windows\system32\drivers\crcdisk.sys


i don't know why this happened cause i just left the laptop at home with my brother and sister at home. i don't know what they could have done to cause this. any help? pls i will really appreciate it. i am a graduating student and i have VERY IMPORTANT FILES in my laptop, i need them for my thesis defense next month T_T

to add to this, the lenovo ideapad y450 has a built-in recovery system so i pressed the recovery button on the laptop and it loaded. it said it detected corrupted system files and it fixed it so i have to restart. but nothing happened. the windows error recovery thing still came out. no luck.

I have a relative with children, he has a laptop and, believe me, they can figure out how to do an amazing amount of damage in just a few minutes!

Since the built-in recovery doesn't work, suggest you contact Lenovo and see what they will do to help. They may be willing to send you a recovery DVD, or they may have some advice that will get the recovery working.

This happened to me last week with my HP desktop and Vista 32 home premium. If you select repair startup option just leave it alone while it repairs. It seems like nothing is happening but after about 30- 40 minutes it restarted and all was well again. I kept on trying things after about 10 minutes and I think that I was just stopping the repair from working. It was only due to the fact that I walked away from the computer in frustration after starting the startup repair procedure for the 4th time and came back after the 30 -40 minutes that I discovered that it had worked.