1. Backup data and start from scratch
2. Backup data and use Norton Ghost or similar
No explanation is necessary for Option 1.
It is well worth considering Option 2.
For this, you need
1. Norton Ghost
2. A spare HD that needs to be ghosted from your C:
Basically you ghost your C: to the spare HD, replace your RAID 1 with RAID 0 and ghost from the spare HD back to C: