I hate Vista/http problem

[#1]

OK, for the last few days I would suddenly lose all access to websites, even our own intranet. I can still ping everything OK and it is the same in FF and IE8. A restart cures it for a while. I ran some AV and malware checks with nothing significant coming up.
I try to telnet to our server. Telnet not recognised. I go to Control Panel ... "Turn Windows features on or off" to enable it. Window is blank. I do some searching and come across this.
The CheckSUR log is full of entries relating to a failed update to do with fixing daylight saving time settings, none of which were fixed. I spend an hour going through the registry deleting all references to KB976098. Now the list is populated in "Turn Windows etc". Great. I tick the box for telnet ... and get "An error has occurred. Not all of the features were successfully changed".
I have had enough now and I am going home.

[#2]

Download putty, it does not only telnet but SSH too, plus you can set up accounts for different telnet/ssh sites and things like that for quick connect.

[#3]

He he, yes, I have found that this morning. Everyone recommends that if Vista telnet doesn't work, give up and use putty instead!

[#4]

Well you would want to use those nasty *nix commands on the lovely M$ OS 
I Used to use putty all the time, till I started using a proper OS   

[#5]

I do use a proper OS at home
I am a bit stumped now, and so is my IT colleague, so I'm looking for ideas. As per the first post, after a certain time browsing, I can't access any websites, even our intranet. I can browse the network, telnet to the server, and can even ftp to external sites. Turning the firewall off and trying another browser makes no difference. All I can do is reboot, but it takes ages after I click Restart for anything to happen. Normally it is very quick.
At my colleague's suggestion, I tried a LSP fix. This says there are no problems.
It all looks like there is something low level on my machine which is stopping http traffic, but only http. Any ideas?

[#6]

I'd take the hard disk out, connect it to a known clean system and do a very thorough malware scan.
If it's SATA (likely) then USB/SATA adapters are cheap and easy to use. Got one the other day which included a separate power supply for under a tenner delivered.

[#7]

I run Avast AV and Windows Defender anyway, and I have also scanned it (albeit in situ) with ClamWin and Malwarebytes. The latter found and deleted some malware registry entries, but nothing else.
If it helps, another symptom I see when http access stops is that when I close Firefox it still shows up in the Task manager processes tab. End process doesn't kill it.

[#8]

You could try a program called Winsockfix.exe. It apparently fixes some of these issues on XP & Vista (Or so I have been told ;))

[#9]

[Moderator's note by Jim (Oldjim): posts relating to a non relevant operating system for this thread have been removed]

[#10]

It seems winsockfix doesn't work on Vista. I have found some more things to try when it next goes wrong. I hadn't realise before that you can right click on the network icon in the systray and get a "Diagnose and Repair " option. I tried it this morning and it said there were no problems, so I'll have another go as and when it goes wrong again.
I have also found this (third reply), which might be worth a go.

[#11]

OK, that didn't work. Still looking for ideas.
Would Wireshark help? I haven't used it before, but I think if I start a capture on this network it could be two or three hours before http fails again, and the log will be huge. What is the bare minimum I could monitor?

[#12]

Seeing as nobody could help with that ;), here is an update. I have uninstalled Zonealarm and am now using the Comodo firewall instead. So far I haven't lost http at all. Looks like it was a ZA issue.

[#13]

How old was your ZoneAlarm?  perhaps it was too old to run, and you needed to get the latest version..... Or, you could have some "permissions" problems with the programs to access the internet/servers

[#14]

Nope - fairly recent version, and kept up to date. Still, I don't care now if Comodo works :).