After thinking about this overnight, I decided to replicate your experiment. I did a fresh install in WinXP Pro SP1 of Nero 188.8.131.52 and InCD 3.40. I then installed Easy CD Creator 184.108.40.206.
The reason I did this is because the Win98SE experiment didn't have the same conditions, and especially because WinXP doesn't use the VXD virtual device driver files that Win98/ME installs. Since WinXP addresses the programs in a different way, I wanted to see how it would handle the simultaneous operation of both.
All program installations loaded without incident, and again both tray icons were available for both InCD and DirectCD. My first experiment was to use InCD to reformat a CD-RW previously formatted by DirectCD. The format appeared to proceed properly and renamed the disc to "InCD", closing by stating that disc was now formatted and ready to use. When the disc was checked in DirectCD and Explorer, it was identified as "EasyWrite_1", which was the name given by the original DirectCD format. Even InCD could find only "EasyWrite_1", and the "InCD" name for the disc had disappeared. This supposed InCD format did not overwrite the name given by the previous DirectCD format, but the disc still retained a format usable by both programs. The name change can easily be done manually in InCD Properties if desired.
I then erased the disc and formatted the blank disc again with InCD. This time the "InCD" name stuck and the disc was recognized with that name by DirectCD. It is also writeable with DirectCD, so your previous statement that a disc can be formatted with either program in WinXP
is true, especially if it is a blank disc to start with.
As far as your comments:
1.) during xp startup (NOW), directcd 5 doesn't autostart, only INCD.
2.) therefore, directcd 5 can still be opened after INCD. (don't know about vice versa - i will check this to be sure - reply tomorrow)
Both InCD and DirectCD are active at WinXP startup. The only difference is that the InCD tray icon is installed by default and can't be disabled by software. In contrast, the DirectCD tray icon is not available by default, but must be selected in the DirectCD format utility | Options | Show Icon in System Tray. Whether or not the DirectCD icon shows in the tray or not is irrelevant to the operation of the program. It is still active all of the time.
InCD does indeed format faster, but in my opinion this is because DirectCD is more stringent in verifying structures and generally more conservative in checking the disc reliability before releasing it for writing.
This is indeed an interesting experiment, and shows that major progress has been made in packet writing software compatibility, at least in WinXP.