Here are the changes necessary for porting NT5 COM plugin back to NT4.

1. Include cppfunc.h. Which redefines the new/delete operators.
2. Simulate InterlockedIncrement/InterlockedDecrement. (pdev.h, common.c, comoem.cpp)
3. Need to define your own _purecall definition (comoem.cpp)
4. Use critical section, init, enter, leave, delete  (pdev.h).
5. Need to export DllInitialize, where at process attach/detach, you need to init/delete critical section for OEM (initdll.c).