Re-partitioning NT Server

Our NT server (4.0 SP6a)was setup up by a consultant as follows:

Raid 0+1
Drive C: 517MB
Drive E: 4.88GB
Drive F: 19.9GB

All partitions are NTFS

Drive C: contains NT only, however it is quite full (97%). We’d like to re-partion, perhapsadding some additional capacity at the same time. What’s the easiest and most reliable route to take? Has anyone had experience with a product like Partition Magic on an NT Server?