Is there any registry configuration in Windows Vista / 7 for messagebox function that make same behavior than in Winsdows XP?
Try this in command windows in both Windows XP and Windows Vista / 7:

MessageBox("This is a messagebox that make an unwanted word-wrap after this ... (AnotherLongWord) in Windows Vista / 7")

Implement a user defined form for messagebox is not an alternative.
Reformating messagebox text is hard, but better solution.
Any other solution, at OS configuration level?