what does this mean? solutions?

I have a win2000 sever with 256ram running that constantly freezes with a black screen as the result.. you can hear the hd “crunching”. i checked the event viewer and the last thing that happened was:

The Network Address Translator (NAT) was unable to request an operation of the kernel-mode translation module. This may indicate misconfiguration, insufficient resources, or an internal error. The data is the error code.

any help would be great.