250GB Caviar hard drive only showing 232GB after format

I have a desktop running Vista and didn’t know the sign on password. To get around the sign on I reinstalled Vista hoping it would install over the already installed version, it didn’t. Now my recovery partition is full because I have 2 OS systems on it and I’m getting a low memory message. A friend said to delete the OS partition and reinstall Vista so I did. Now if I go to Disc management it only list one disc at 232GB and nothing else. I looks like I deleted the OS partition but I want to recover the 18GB that I deleted. I used Data Lifeguard and it sees that it’s a 250GB hard drive but it only list 232GB of storage. Does anyone have any ideas how to fix this?

There are some utilities out there that can do a non-destructive re-partitioning of the drive to merge the unallocated space to the existing partition…