In the process of doing some disk cleanup, I noticed there was a drive D: called DATA that had half my hard disk space sitting there doing nothing.  So I deleted it but now the disk space shows up in the C: drive as unallocated.  Please note this Acer laptop was originally a Vista machine that I upgraded to Windows 8.1 and I am no IT professional, so the upgrade wasn't as smooth as I wanted it to be but in general the machine works fine.

BBA

Not quite sure what the question is but will take a stab at it.  YOu now have a "C" drive and lots of unallocated space.  I suspect you want to add that to your "C" drive.  If that is the case the easiest way to do it is using a 3rd party app called EASEUS Partition Master 10 (it is free)

After downloading and installing you select the "C" drive and click "expand">move the slider to add all the unallocated space. and apply the change.  It will probably ask for a reboot  

http://www.easeus.com/partition-manager/epm-free.html