I have a Hitachi external hard disk, I have tons of extremely important files inside. It was still working fine last night until this morning. This is what happened: I plugged in the hard disk, than it is seen as Local Disk (h:). It prompts me to format the disk once I double clicked it.

Please help me!! I have really important files in it! Thanks lots in advance!

I've tried reading this
External WD not being identified - Local Disk (h:) : Hard Disk Drives: data recovery and repair

but I couldnt understand, can someone tell me if it works and how to do it? Im not good in this kind of things.

Please help, thanks!

So long as the external drive wasn't dropped or had some kind of shock in some way, I'd start by downloading get data back for ntfs and use the free trial to see if your data is still there. You see what it can recover before you pay for it. If you like the data you see, you simply pay for it and use it to recover your data.

You can also try a download of r-studio and as well.

You mean I should re-format it first? Since it cant scan it if I dont format it.

NO ! Do NOT reformat the drive ! Remove the drive from the external enclosure connect it to your main desktop computer on another sata port. Download either GetDataBack from http://www.runtime.org/data-recovery-software.htm or R-Studio install that on your boot C:\ drive then use the software to scan the drive for any data it can recover.

Sorry, I forgot to include that Im using a laptop.
External enclosure meaning the casing of the Hard disk?

Sorry Im really lousy with this kind of thing.

I recommend you to use R-Undelete rather than R-Studio. It has the same data recovery engine, but is much easier to use. You may read more about how to recover files using R-Undelete in its online help.
Your case is "Recover lost files from a deleted logical disk".
You may test it for free in its Demo mode.

_________________
R-Studio Data Recovery Software