Ok people, now it's my turn to ask for help. I recently changed computer, and I moved from Win98 to Win2000. I installed my old version of Nero (5.5.9.9), which can be installed on Windows 2000. Well, the first startup goes correctly, the program asks for the serial, I register the software and all launches correcly. But if I exit and open again Nero, then nero Express starts, and I have no possibility to switch back to Nero Burning Rom standard interface. Please note I have read Ahead's Win2000 information page at http://www.nero.com/en/content/c1015839577540.html but I found no clue there. Any suggestions?
OK I solved my own problem. I post this here so everyone can benefit of that. The 'switching' between Nero and Nero Express is allowed only if you have a registered version. If you have an OEM version you cannot switch. In my case, the problem was simple (well, now that I found it!). I just wrong-typed the registration code. I re-typed it and...voilà! Nero unlocked and I have again the possibility to switch between professional Nero interface and Nero Express interface.
