multiple msn, manually

in Messenger setup dir，there is: msnmsgr.exe，backup it first，then open msnmsgr.exe by hex editor such as xvi32，searching:
00 FF 15 C0 15 40 00 3D B7
change "B7" to "B6" =>
00 FF 15 C0 15 40 00 3D B6
my test of 2 versions:
8.0.0792 yes
8.0.0812 yes