Using Total Commander (or any registry tool) to hack your registry can make your phone unusable. DO SO AT YOUR OWN RISK. Now that I've warned you, here are some things I've found useful.
Total Commander lets you manage not just the file system but the registry of your smartphone. I've found that it works on both the Orange SPV c500 and c600.
Clicking your joykey on the top item "\\" will get you into the registry registry
On the c600:
On the c600 there is an Expert Mode icon on the Orange Home Screen. It allows you to assign programs to one of four entries. If you use the tick box to turn this option off thre appears to be no way to switch it back on again.
Change Value from 0 to 1 and OK
Change Name of Phone