The Rinex converter within MSTAR is not Y2K compliant.
Do not enter Rinex files directly into MSTAR.
You must use the stand-alone Rinex converter, Rinex190,
to convert Rinex data (O and N files) to Promark
files (*.car)

Download rinex.zip to your PC.  Unzip the rinex.zip 
file.  Be sure the 2 *.dll files  reside in the same 
directory as the rinex executable.  Start Rinex190 
by clicking on the Rinex2.exe file.

If you have any questions, please call Technical 
Support at 800-229-2400, or 408-615-5100.