What you've got there is most likely some form of protected recovery partition, put there by the guys that made your PC for when something goes wrong.
Removing it is difficult and risky, the only safe advice I can give you is to try recovering as much free space as possible.
Right click the drive on My Computer, select 'Properties'
Now hit the good ol' Disk Cleanup button
You've probably done this before, tick the various boxes selecting junk to remove (Just the one for me).
Now, select "More Options" along the top, this is often where big space gains are to be found.
On this page, select the "Clean up..." option in the "System Restore and Shadow Copies" section.
Yep, delete. If your computer seems to freeze at this point, give it a moment, it's deleting the old junk.
Now you can simply click OK, select "Delete Files" on the pop up box, and you're done.
On most 1-2 year old systems, this can free up in excess of 5GB. Try it on both your 'C' and 'D' drives.
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Alternately, you could try this method to delete the partition, although it may not work, and I do not recommend it.
Open up "My Computer", right-click on "Computer" and click "Manage".
A new window titled "Computer Management" should pop up.
On the right side of this window, click "Disk Management", after a bit of loading it should show all your hard drives and the like.
In the pane at the bottom, right-click the drive you want to delete, and click "Delete Volume". (If this option is grayed out, the partition has some form of protection on it and cannot be deleted easily, without re-installing Windows.
Click "Yes" on the prompt, now you've got some "Unallocated" space. Right click on the drive (Probaby C in your case.) and click "Extend Volume..."
This lovely Wizard should come up, from here it's a simple case of clicking "Next" over and over. It should then start the expansion process, which may take some time (5 minutes - 2 hours, depends on drive size etc.).
If all went well, your old partition should be gone and all that lovely space will be reclaimed.
On a side note, having Windows on a small partition at the start or end of the drive makes so little difference these days that it doesn't matter at all. I'd also recommend you do not put Windows on it's own smaller partition as it will soon begin to run into issues with not enough space for temporary files and the pagefile (I know you can move these, but most won't). It's also pretty much an outdated procedure, the only real use of it being that it's arguably easier to keep track of files.
Removing it is difficult and risky, the only safe advice I can give you is to try recovering as much free space as possible.
Right click the drive on My Computer, select 'Properties'
Now hit the good ol' Disk Cleanup button
You've probably done this before, tick the various boxes selecting junk to remove (Just the one for me).
Now, select "More Options" along the top, this is often where big space gains are to be found.
On this page, select the "Clean up..." option in the "System Restore and Shadow Copies" section.
Yep, delete. If your computer seems to freeze at this point, give it a moment, it's deleting the old junk.
Now you can simply click OK, select "Delete Files" on the pop up box, and you're done.
On most 1-2 year old systems, this can free up in excess of 5GB. Try it on both your 'C' and 'D' drives.
Alternately, you could try this method to delete the partition, although it may not work, and I do not recommend it.
Open up "My Computer", right-click on "Computer" and click "Manage".
A new window titled "Computer Management" should pop up.
On the right side of this window, click "Disk Management", after a bit of loading it should show all your hard drives and the like.
In the pane at the bottom, right-click the drive you want to delete, and click "Delete Volume". (If this option is grayed out, the partition has some form of protection on it and cannot be deleted easily, without re-installing Windows.
Click "Yes" on the prompt, now you've got some "Unallocated" space. Right click on the drive (Probaby C in your case.) and click "Extend Volume..."
This lovely Wizard should come up, from here it's a simple case of clicking "Next" over and over. It should then start the expansion process, which may take some time (5 minutes - 2 hours, depends on drive size etc.).
If all went well, your old partition should be gone and all that lovely space will be reclaimed.
On a side note, having Windows on a small partition at the start or end of the drive makes so little difference these days that it doesn't matter at all. I'd also recommend you do not put Windows on it's own smaller partition as it will soon begin to run into issues with not enough space for temporary files and the pagefile (I know you can move these, but most won't). It's also pretty much an outdated procedure, the only real use of it being that it's arguably easier to keep track of files.