(This seems similar to an issue in "Vista Internet connection stops working until reboot" but has quite a few differences, so I'm posting it separately.)
I have Windows Vista Home Premium.
With alarming regularity, any and all http requests simply die. I can't find any rhyme or reason for it. It can happen 20 minutes after I start my browsing session, or two hours.
My network connection does not go down, and no other protocols seem to be affected. (I can connect to WoW, can use POP and IMAP, DropBox continues to update files, etc.) I can still ping website addresses, but the browser simply refuses to connect.
More unusually, it kills it for all browsers. If I'm using Firefox and it dies, then start up Chrome, Safari, or IE, none of them can load any pages either. The loading indicator just "spins" forever. AJAX HTTP calls are similarly affected. (Gmail doesn't update while I'm in this state, for instance.) Only a restart has been effective in clearing it.
I'm connecting through a Linksys router, but none of the other PCs (Win XP and Linux) on my network are experiencing this issue. Only the Windows Vista machine is so affected.
I'm hanging on for Windows 7, but am afraid that it won't fix the issue. I am religious about keeping the OS and software up-to-date with patches.
How can I fix this? What should I be looking at?