I Have a 200 GB hard drive. So far I had two partitions:
50GB System partition
150GB additional partition for various data
I decided that I didn't want to keep the additional partition, so I used the Windows 7 installation disc to format and delete this partition. Then I extended the system partition and added the unallocated 150GB to it. Everything seemed fine and it looked like the system partition now had 200GB.
Then I restarted and noticed that in My Computer it still says that my C:\ drive is 50GB large. I downloaded Partition Wizard Home edition, and it shows no unallocated space - just one system partition of 200GB!