For curiousity's sake, I tested my work XP box today, first as usual, then after a reboot and disabling the network connection:
http://test.winehq.org/data/b4bf3553c4071a2a6979f1df08ae75aadde94b4b/#group_...
http://test.winehq.org/data/b4bf3553c4071a2a6979f1df08ae75aadde94b4b/xp_aeng... http://test.winehq.org/data/b4bf3553c4071a2a6979f1df08ae75aadde94b4b/xp_aeng...
Most of the tests came out the same, with some spurious failures in MSI/dinput/user32/etc. The interesting ones would be the urlmon/wininet. Some of these tests timeout (urlmon: protocol/url, wininet:http) , some failed (msxml3:domdoc), and some still passed(!) (wininet:ftp, wininet:generated, wininet:internet, wininet:url, wininet:urlcache, ws2_32:protocol, urlmon:misc).
I haven't tested wine yet, as I can't bring down the network connection on any of the boxes I can currently test on, but I'll do so when I next get a chance. Either way, seems some of this behavior could be made more consistent (if network connection is down, either skip or timeout, but don't fail). I may try later with leaving the network connection up but removing the internet connection at the router...
-Austin