This is something that has always bothered me, yet I never really investigated it until now.
It always bugged me that shared folders would become inaccessible ie, you get the message: “you might not have permission to use this network resource” when you make some change to network settings. The annoying thing about this is that it would all fix itself at some unknown time in the future (from 10 minutes, up to 10 hours).
Well this happened when I changed a customers PC from fixed IP to DHCP. After that, none of the other computers in the office would be able to see the shared folders on the main PC… It all came right after a few hours (after I had gone).
Well, the next time it happened, I used: ipconfig /flushdns (and followed by a related command: ipconfig /registerdns).
It seems to work sometimes… yet other times, it seems to have no effect.
It seems to have no effect if the network settings have been corrupted by an infection… in which case, a reinstall of windows seems to be the only option 🙁