Repeating my previous post:
1. Run the V5.0 license transfer program on the old computer to get your license.
2. Install V5.0 on the new computer. Don't try to use it or even activate it.
3. Use the license on the V5 in the new computer. Make sure it is working before going any further.
4. Install the 5.5 upgrade on the new computer.
There are some pitfalls in the road: