When i try to open a 3/4 time midi in NWC it opes it as 4/4 time. Is there any way to fix this?
See if it works to move to the beginning of each staff, change the time signature, and run audit bar lines from the tools dropdown menu.
The audit bar lines will give you a strange result if the number of notes and rests aren't evenly divisible by the top number in the time signature, so save the file before you run the audit.