Considering your story, the likely cause is that all the unexpected re-starts ended up writing a little confused data to the external HDD so it can't be recognized properly, but almost all your data is still there. Now ONE of the many ways this can happen is in the File system data on the disk, so let's check for that using Windows Disk Management.
With the machine running in windows, click on Start and then RIGHT-click on My computer. In the mini-menu click on Manage to open a Computer Management window. On the left expand Storage if necessary so you can choose Disk Management.
Concentrate on the LOWER RIGHT pane of this window where you can see a series of horizontal blocks, each representing a hardware storage device. The window scrolls so you can see them all. Each block will have a small sub-block at the left end with some label info - a name like "Disk_2", a size, and a bit of other data. To its right will be one or moe larger sub-blocks that each represent a Partition on this drive. The data in this will show the letter name of the drive like "E:", a volume name it was given like "Darren's Disk", a File System like NTFS, and a size. If the file system is RAW, we have found the major problem. I have not done this, but it is well known and more importantly, how to fix it is known. Search the new for how to recover and use a drive with a RAW format.
If the drive's File system is already NTFS, then the problem is something else. Does the Partition have a letter name like E:? If it does not, RIGHT-click on it and choose to Change its name to some letter not in use. If you do this, back out of Disk Management and reboot for the change to take effect.
If neither of these items is wrong in Disk Management, tell us what it does say and maybe someone can recommend a fix. You are right NOT to follow Windows' (dumb) advice to Format this disk now.
First the link on how to recover a boot sector does not work.
Secondly, I did check through disk management and it is RAW. What should I do now? (I couldn't find anything useful in the news). Recovering the files will be difficult as I don't think I have space on the other HD's to save them on. Is there anyway I can fix the drive without having to save the copy the files elsewhere and then reformat?
I am currently trying to use GetDataBack to see if I can fix it but it is going incredibly slowly (It has been running for over 24 hours and is only at 6% with nothing discovered; its a 1.5TB drive, so maybe that's why)
uhh, i know that it has been a year since this is posted here on this web site....
but i found a way, using a vista (probably similar to xp)
BE WARY THAT THIS WILL FORMAT EVERYTHING IN YOUR HDD/FDD. DON'T BLAME ME FOR ANY DATA LOSS.
1) Follow the earlier instructions of how to open Disk Management Windows.
2) Open Disk Management, and see the below part of the window (below the part where it shows every disk connected in the computer). You'll see the disk number, the size, the format and the status of your disk (Healthy(Primary Partition), for example). The one shows the size of your HDD and below says "Unallocated" is your HDD.
3) Since your disk format now is RAW format, right-click on the table where it says "Unallocated". Choose "New Simple Volume". This will take you to a new window.
4) Follow the instructions. During the process, it will tell you to "Assign the following drive letter". Assign any as long as it didn't overcross others that is using it. Format the volume using the default settings, and DO NOT check the "Perform a quick format" checkbox. It is as a precaution method.
5) Format the disk, wait for about 5 mins (1GB Flash Drive), and you're done!