Lost ability to ping in dos box

I don’t know what happened because I’ve never had a problem using the PING command from a DOS box in Win98se to check connection problems.

I type:
c:\ping www.yahoo.com

Tonight when I tried it, however, it replied :
This program cannot be run in DOS mode.
What could have caused this? The only thing I have done different is I recently installed StarOffice 5.1.