unc path

i am having a problem accessing my main server using a UNC path which worked before yesterday. I can access it from “My Computer” and I can see everything but Like remote desktop wont work using the unc path but will work using the IP adress. I am using ACT 9.0 from sage software and it uses a unc path only and wont work. My company is basicly shut down with out it running. Any ideas would be a big help