SYMEVENT.SYS error

I have NIS 20 installed on an XP system and get the message:

"-- C:\Windows\ systems32\SYMEVENT.SYS. An installable Virtual Device Driver failed Dll initialization. Choose "Close" to terminate the application"  with buttons to CLOSE or IGNORE.  The problem occurs with 3 16-bit prgrams that I still use.  If I click on the IGNORE button the programs execute and seem to be OK.

 

Is SYMEVENT.SYS needed on my PC?  I cannot remove it in Windows b/c it is "in use by other programs"