Is the file NP_MON.SYS located on your computer? Then your computer is infected.
We do suggest you should remove NP_MON.SYS from your computer as soon as possible.
NP_MON.SYS is Trojan/Backdoor.
Kill the process NP_MON.SYS and remove NP_MON.SYS from the Windows startup.

NP_MON.SYS Information and Removal:
NP_MON.SYS is known as: Spyware.MSNChatSniffer!rem [PCTools] Spyware.MSNChatSniffer [Symantec] Generic.dx!tct [McAfee].
MD5 of NP_MON.SYS = 92B001A8EFDEBCDA4DB3DAC0BE3A9C74
NP_MON.SYS size is 24514 bytes.
Full path on a computer: %SYSTEM%\DRIVERS\NP_MON.SYS
Related Files:
%DESKTOPDIR%\MSN MONITOR & SNIFFER.LNK
%PROGRAMS%\MSN MONITOR & SNIFFER\MSN MONITOR & SNIFFER HELP.LNK
%PROGRAMS%\MSN MONITOR & SNIFFER\MSN MONITOR & SNIFFER.LNK
%PROGRAMS%\MSN MONITOR & SNIFFER\UNINSTALL MSN MONITOR & SNIFFER.LNK
%PROGRAMFILES%\GJPSOFT\MSNMONITOR\INSTALL.LOG
%PROGRAMFILES%\GJPSOFT\MSNMONITOR\MSNMONITOR.CHM
%PROGRAMFILES%\GJPSOFT\MSNMONITOR\MSNMONITOR.EXE
%PROGRAMFILES%\GJPSOFT\MSNMONITOR\UNWISE.EXE
%SYSTEM%\DRIVERS\NP_MON.SYS