How do I retrieve data previously stored on the hard drive

click start right click on my computer you should see your drive select properties click tools check now tick both boxes automatically fix files and scan for and attempt recovery on any bad sectors then select check now

start should schedule this task when restart if this is the hard drive with your operating system on it
i have found the best results ticking one box and wait until its finished then return and tick the other box
do not do anything while the chkdsk utility is in progress any input may damage your computer
also
there are many freeware data recovery programs available on the internet and many pay data recovery programs
http://download.cnet.com/easeus-data-recovery-wizard/3000-2248_4-75184619.html

http://download.cnet.com/pandora-recovery/3000-2094_4-10694796.html

Your memory card has a certain amount of space dedicated to storage and you can continuously take pictures for storage. Once that space is used up, new pictures will overwrite anything that is old on the card. Probability of recovering anything deleted highly unlikely.

What do you mean? Install software on it? Or save files to it? External drives are primarily for storage purposes, and not for installation purposes.

If you are looking to install something on it, then you have it for the wrong reasons. It's main purpose is to store files.

network attached storage server using bsd.used for backup
www.nas.org

May be that is hidden..Go to the control pannel look for folder options and then in the view tab check the box show all files and then click ok.

connect it again see if are able to see your files again. if not then there are data recovery tools available on the internet.

But i think the first method will solve your problem

It should plug in as a Windows Storage device.This will appear as another drive on the computer.
Copy the file across the "new" drive.
Then ask windows to stop using the drive  by clicking on the USB device icon and selecting stop storage device.
Then you can disconnect it safely.

Assuming that the external hdd is physically working fine, everything is pointing to a damaged boot sector.

You can get back most (if not all) your data stored in your external drive with the help of an application called: Pc Inspector File recovery.
Its a freeware.
Here is the link: http://pcinspector.de/Sites/file_recovery/download.htm?language=1#

Simply install it on your C:\ drive, and follow the prompts.
Please let us know the outcome.

Don't forget to rate this answer if it helps

It sounds like your hard drive is all locked up. Don't worry you can have the data retrieved from your hard drive by using this online company that I highly recommend:
http://www.gillware.com/

Try formatting the drive. Assuming Windows XP, just open your "my computer" icon, right-click on the device and choose format. Be aware, formatting will remove any data you may have had on there previously.

If you're using another OS, or if it's an existing drive, please re-state your question giving further details (what OS, what you are trying to retrieve, etc).

Yes you can get your space back.
Let me clear you first you lost the space due to while system is writing data in your SD micro card it is suddenly ejected or disabled.

You will do this method to retrieve you data back. You will need some things
1. Card reader for SD micro memory.
2. A software called D M comes as Hard disk tool it comes in bootable cds.

You will remove your H D for safe side to protect your hard disk data.

Put your SD card in card reader and start you computer with bootable cd that contains D M software.

When your system is boot from cd run D M and go to option in D M erase all data. This will retrieve your all space from SD. Remember you can do the same thing with Hard disk if there is any bad sector or some space not avalible or disk partion is not able to delete by any softwares.

Hope this will help you, If you have any problem regards this you can reply to me other wise don't forget to make ansewer my thread.

Regards
nidostyle