How you can retrieve very important documents from computer which have a problem in its operating system ? you can't access the hard disk..

1 - There are so many Third Party Software which can help you to backup your data in this kind of salutations.

2 - one other way to retrieve you data is, Remove the Hard disk from the system and put this hard disk into external Hard disk case and use as external hard disk and copy your important data to other media. 

Format it using Windows7. Go to Windows old file location at C and you will find everything of the previous users of that particular machine

If the hard drive is not damaged,

Access the data using a another OS, like Knoppix bootable CD.

or

Extract the hard drive and plug it as an external hard drive on another computer (working fine)

or

If the disk is partitionned, the OS is on partition A and the data on partition B, then simply format partition A whit no risk of loosing the data. 

You can try trinity boot disk or partition boot disk

go to the safe mode by pressing f8 then u can able to access 

the files on ur drives

you need to repair windows and it is possible as long as you have the appropriate repair CD and you would then have access to the hard disk. it is even easier on a pc for which you set up a back up

There are some tools or micro-software which can boot from the CD and allow you to access the hard disk Drive and make copy of the data.

I used one of these software called MiniTool Partition Wizard Home Edition it is very useful and powerful tool and free !

It is easy to use just download the setup and put burn it on CD. then put the mini tool CD in your computer and power on it but you must enter the BIOS setup and change the boot sequence or force the computer to boot from the CD-ROM not from the hard disk.

once you boot from CD-ROM the mini tool will operate and allow you access the hard disk and flash memory so you can copy files from one to another.

here is the link of mini tool

http://www.partitionwizard.com/free-partition-manager.html

Please provide more details next time.

If the Operating System is corrupt, you can use recovery console, or just boot in console mode.

You can take out the hard disk and plug in another computer or use external hard drive case.

You can make a bootable USB disk, and recover your documents.

1. Remove hard disc and connect it to other computer

2. Use external system from CD (Live version) or USB (for example Linux)

3. Use recovery software

4. Try fix system 

Every solution depends of situation

if u have work on HBCD ... the use mini windows Xp... and retriew ur documents.....

if there is some files missing in OS.... and u r not able to LOgOn to OS(windows desktop).....

Could you please let us know if you are accessing a computer through a network?