Old IBM 28Gb HDD in two 14 Gb partitions. Tried to access with USB adapter, No Drive Letters. Couldn't assign a new letter. Deleted the first 14 Gb partition, it collapsed to 500Mb, but now I could make a new volume and assign a drive letter. Deleted the second 14 Gb partition and it changed to 14 Gb unallocated; was able to make new volume. But the first partition disappeared and now the drive is only one partition of 14 GB. How do I get the full 28Gb? Don't need and data on the drive, I want to start it anew. Windows 7.