Web Server… Asleep?

When I have been working on my server, I am able to access my webpage. However, when I leave the office, it seems to go to sleep. I have already disabled the power save modes for everything. The only way to access this system is through the IP address. I have not accessed it outside the office successfully yet. I am running a front page 98 server on windows 95 with 32 megs and 200MHz (stone age, I know). I dont think the problem is DNS since I get a server not found error, but it could be. I have done nothing with DNS if there is something I need to do.