At my company, we use two software packages to accomplish this. Inventory personnel use MAS 200 by Sage Software. The user interface can be cumbersome at times, but it is very sophisticated (so much that I don't know every little detail about it). It can manage purchase orders, inventory...
As mentioned above, a null modem cable must be used. If you don't know what it is, it basically internally swaps the transmit and recieve pins (pins 2&3) as (well as the RTS and CTS pins? - can't remember that part). If you don't mind transmitting slowly, you can use Hyperterminal to transmit...
Obviously "memory leak" is a term that can apply to both the OS and a specific application. I've seen both cases. However, it has been my experience that it is very common in both MS applications and OS's. As hacksaw mentioned, one of their many "un-documented features".
Since you've had it for such a short time, I'd RMA it back to the place you got it and try a new one. I've had defective mobos before. Also, because the failure to load the OS and other devices seems to be sporadic (e.g. it fails at different times and sometimes loads Windows), you may want to...
I believe there is a utility in Win98 called MSConfig (you can run it by going to Start->Run and typing msconfig. There you can configure which applications and/or processes load when Windows loads.
As far as the memory leaks are concerned, that's just Windows for ya. There are tools...
Yet another option is to purchase a router. These are relatively inexpensive these days and also provide hardware firewalls. The one I own is a 4 port Linksys cable modem router and both of my PCs have no trouble connecting to the internet, PC1 dual boots WinXP Pro and Linux Mandrake 9.0, PC2...