No space on hard Drive but

data may be hidden in your drive due to viruses.
for windows Xp, follow thes steps

1. From my computer menu bar click on tools
2. then click folder option
3. in view TAb click on show hidden files and folders
4. scroll down the list of view TAb
5. uncheck the option "Hide protected operating system files (recommended)"
6. after this check your driver. there might be some file and folders

Depending on the Operating System you are using (i.e. Windows or Mac OSX etc.), they deal with deleting files in different ways. In the case of an Apple Mac, it doesn't actually delete you files, but instead moves them to the recycle bin which is located ON your external hard drive. This means that in order to make the space available, you have to empty your recycle bin on your desktop whilst the hard drive is plugged in and it will empty the folder for you. Or look for a hidden folder on the root of your Hard Drive called Recycle and delete it (it will be recreated by your system when your system needs it).

Alternatively, 1TB is a large drive meaning that it is possible that your file structure has become "fragmented". Don't worry yourself with the specifics, but if you right-click on the drive and access the Properties, choose the Tools tab and use the Defragment tool. Also it might be worth using the Check Disk For Errors option, although Defragment is more relevant in this case.

If you run through these basic troubleshooting steps listed above I hope you will gain access to your cleared space.

please check if the files are hidden. just go to the explorer -> tools -> folder option -> view tab -> then on the Advance Settings click the Show Hidden Files and Folders. then try to navigate your external hard drive.

you should be able to connect the external hard drive to your laptop and the drive should show up under my computer. Then just drag and drop or cut and paste any files you want to move to the external hard drive.

hope this helps.

How many directory deep is the file going that you are trying to save? I believe the maximum NTFS file (location + name) of file length can not exceed 256 characters total.

Example: C:\user\documents\file.exe is OK

But: C:\user\documents\folder\folder\folder\folder\folder\this folder name 230 charicters long\file.exe BAD

If the explorer shows you have some space left and can not create any file or folder, it might be because of heavily fragmented drive. try defragmenting thr drive using any application. I usually use O&O defrag .

you could make sure your viewing all files such as hidden files by going to view-folder options-view- all files.
alternatively you may be able to use a program for restoring old deleted files.

Have you tried showing hidden and system files?
In the Windows Explorer, go to the Tools menu and select Options or Folder Options.
In the View tab, scroll in the list and make sure show hidden files is selected. You can also unselect the 'hide system files' option.

That will show you anything on the disk!

Jules

is the 100Gb divided into 2 partition?
since you have done the show all folder and files. and nothing else show up. you can do a defreg. to compress the drive. you may have lots of fragmented files. (that account for the lost space).

Try to defrag the disk.