hi,
1. use Safedisk unwrapper (or unSafedisk) to remove the cd-check protection of Safedisk.
2. use a fileanalizer to look whether the exe is packed or not (If it is packed use the unpacker with that it one packed)
3. Load the exe in w32dasm - The now are StrRef's
4. Look of the error-message
5. use hiew and "patch" the Place
PS: All this is not so simple. Experience and programming knowledge in assembler are a condition.
Sorry for my bad english.
Good luck