Y'all are all much sharper than I am, but just in case anyone else is having this issue, it's a simple fix. Last night I got my laptop to start copying some files over from my server in preparation for a 10 day trip down South for my Mom's 90th birthday. I had Internet access and I could see my server but I couldn't connect to it. Kept getting "Windows cannot connect the \\SERVER...." error.
I have a Cisco (Pronounced "Linksys") E2500 (I think) Wireless N router and just like my old Linksys router it has to be rebooted periodically, though that's not the usual alert I get. So I decided to reboot the server while I was at it. When I took it down, it started the usual "Configuring Updates" bit so I sat down to wait. Finally shut down and I unplugged the router and modem and waited a minute or two then powered everything back up. 30 minutes later the server came back up after configuring then removing the updates then restarting-configuring-failing-removing-restarting. Came back to my laptop, no server at all. By then it was after 1:30 am so I went to bed. Had a doctor appointment so around 2:00 pm today I got back to it. Looked at the updates, nothing out of the ordinary but when I went to my sharing settings, everything was turned off. Turned it all back like I had it and it's fine.
So, if your network suddenly went down there's the culprit. Don't know why the updates took so long to apply. I'm fairly certain I've rebooted my server PC since last Tuesday yet all the updates are dated 2/13/2013.