Os is not booting

Step 1 is tell us what BRAND and model of hard drive you have.

If you do not know how just ask., someone will help

The reason I say that is to check if you have a Western Digital hard drive.

If it is not from WD you may better helped at better forum etc ?

I’m curious if you have been using windows 8 at all and what model laptop you have…

I have heard of issues with UEFI secure boot stuff and also dual booting with windows 7.

And also is your windows install factory installed from an oem company like HP or Dell etc ?

Because they often have recovery partitions.

Based on your comment I take it you have a windows CD.

I would do what the other guys say first and try and check your drive with WDdiag.

But after that I would probably put your windows disc in and try a repair computer option

but you said that didn’t help so after that I would try and load the CD/DVD in and wait until

its loaded up and hit shift+f10 to open the recovery console and try using chkdsk.

CHKDSK [drive letter]: /V /B /X

for example:
chkdsk c: /v /b /x

The /B part is key it tells chkdsk to re-evaluate bad sectors and
to update its own “bad sectors” tracking file.

and pay attention to the console data because its the best source for info as to what happened…

The only other way that result data is logged is in the windows event viewer.

win7 log only in event viewer…
Event Viewer and navigate to Windows Logs / Application.
In the right side section, look for:
Source: wininit
Event ID: 1001

(or search for wininnit in the panel on the right)

And note that data results can be cut short if they are too big for the event viewer buffer

so its better to pay attention to what the console says when your running it etc.

Also the command I posted above only checks your C drive, so if you have other partitions

you may want to rerun the commend with each drive letter ?

Type in this,

chkdsk /?

To see the program info in the console.

This may say that it repaired files be becareful because they may not be actually fixed

and you could end up with corrupt files still corrupt… So if you get booted up I would run a new command asap…

Open run then cmd and then type in sfc -scannow

that will verify all your windows related files are not corrupt or damaged etc

It will also automatically try and fix any of them too.

The results will be stored in this path / file on windows 7

C:\Windows\Logs\CBS\CBS.log

You can then open that with a text editor and scroll to the bottom and see what files

may have been detected as corrupt and whether the repair attempt(s) succeeded or not.

good luck