1 user connected to my machine?

I rebooted my machine yesterday and I got a message saying something like " there is 1 user(s) connected to your computer...do you still wish to shut down". I did shut down as there shouldn't have been anyone connected... how can I find out how they conncted? I am a part of a home network, but the other 2 computers were not being used at the time, and I've rebooted before with the others being used and never got that message before. Methinks I been hacked...
can anyone point me in the right direction? Systems are running Win98SE...

 

under DOS try the command "net session" see what that gives you

 

I dont mean DOS DOS but the command prompt under windows

 

"the command SESSION is unknown. for a list of valid commands type NET HELP at the command prompt. "

 

doh, lets see.... try netstat in commadn prompt

 

ok...using netstat I see a few lines with numbers relating to my ip number and my isp...
but this morning when I first got on the cpu, with nothing open or running I had one line that had "nbsession" which I hadn't seen before. I rebooted normally and then it was gone...

 

nbsession line is there again right now...here is the text"

TCP voodoo:nbsession 0x5358447b.esnxx2.adsl-dhcp.tele.dk:4196 TIME_WAIT

pretty sure this is the culprit....what can I do about it?

 

check this software out, supposed to scan your open ports and tell you what software is opening the ports, should tell us what that it and if its possibly a trojan

http://ntsecurity.nu/toolbox/inzider/

 

ok..that line hasn't shown up since I d/l that program...as soon as it does I'll run it again and see what shows up
thanks Wookie

 

that happened to me and i called hp he walked me through diasabling some things at the start up ..it probably was just u running 2 programs