I have networked 2 pc together and have shared one folder and the internet connection. Now, Is there anyway to flash a message up on the screen of the other computer.similar to using a messenger service, Main PC is XP PRO and second machine is 98se.
Yup there is, you can open a DOS prompt and type net send followed by what you want to say OR use something like this here http://www.rpland.net/netsend/ which gives you a GUI interface.
The ONLY problem with this is that it uses the messenger service, which Microsoft will disable in SP2 due to the security problems that it has, as it was the target for the MSblast worm a wee while back.
Still if you have an uptodate firewall/virus scanner you should be OK.
There was a security bulletin out a while back that advised users to turn off the "messenger service" since it is intended for business network management.
When I went to turn mine off it already was. Seems to be random (or a function of which patches you've accepted) whether yours is on or not.
If you feel you need the serivce right click my computer select manage select services and apps then services look for and double click messenger then in the pop up window hit start or stop as desired. It must be turned on on allcomputers. Note this service has nothing to do with IM, MSN Messenger, etc.