I had the same problems.

I am running windows 7 and 8 on two machines using IE 8 and IE 10 respectively.
It would take IE 8 and 10 about 40 seconds to load a page, yet FireFox 17 continued towork flawlessly.

I traced the problem to ZoneAlarm Pro 11 that had IPv6 enabled. I disabled IPv6 in ZoneAlarm Pro 11 as follows:

	- Internet Protected Box - View Details
	- Computer Tab
	- Advanced Firewall Settings (also should be On)
	- Advanced Settings
	- Uncheck "Enable IPv6 Networking"
                            - Reboot

That fixed my problem. IE 8 and 10 now work flawlessly.

You cannot enable IPv6 (in ZoneAlarm 11 or maybe other Firewalls) when your ISP or router does not support IPv6

Hope this helps.

EdwardB 6-5-2011