no problem
i'm sure there is an easier way of doing this, but this is how i always check, we can use the sysedit.exe or command.com applications which are built in on the xp o/s as an example
launch either one from the run box
check your task manager, if you see a new process there named ntvdm.exe, it means it's using a 16bit subsystem (NT Virtual Dos Machine), that's how i tell if it's a 16bit app., so do the same thing with some of your apps. that you're curious about
a lot of the time you'll notice the app. may not be 16bit, but they use an old 16bit installer, like old InstallShield versions, so that may create some roadblocks too, but overall, not many 16bit apps. left on the market