Windows 7 taking over a minute to login

If you don't know what changed it, chances are we don't. Any new program installations? Did it happen after a certain OS update? Is this the RC or the RTM we're talking about? Did you add any more users? Change hardware? Just try to think of anything to do with the PC that would have been different between the last time it worked fine and the first time you noticed the 1 minute login times.

I'm pretty sure it's not a virus, i have AVG actively protecting my computer and run Malwarebytes' scans regularly. It wouldn't be a rootkit would it? Does Malwarebytes' detect rootkits?
EDIT: Actually there is one recent piece of software I haven't removed and that is Microsoft Office 2007, I wouldn't think that that is the reason for the slow login times though. Unless it is running some sort of startup service in the background but I have looked through the services and seen no such thing.

The computer and installation are both only about a month or two old.

Before the OS presents the desktop, it loads any start-up scripts, security configurations, additional drivers and services that you may require or have installed. My suggestion is add another user, log out and log in as the new user. If the problem goes away, then its something that your normal user account is loading, probably a start-up program or a massively big file in the Documents library.

If the problem persists with the new user, then its a computer or OS-related problem, most likely caused by a bug, glitch, or an update that switched on something that's not necessary and very memory-intensive (possibly a memory leak).

Defragging wont do anything for you, might as well cancel it. Since Vista, Windows has been defragging your hard drive in the background while your processor is idle, one of the many reasons why people complained about so-called disk thrashing, or unusual activity. Rather perform a disk cleanup, and go check msconfig to see what programs are starting up. If you find anything with the box ticked that doesn't have a name next to it, disable it from start-up immediately, because that's usually malware or an orphaned file.

Okay, so I tried enabling the guest account and restarting my computer and logging into that first. It still takes just as long to log in. However, once logged into the guest account i could log off and log into my administrator account within a couple of seconds. So, do you have any suggestions of where I should go from here?

It's wireless, should i just disable connect automatically?

IT COULD BE A MISSING DRIVER!!!!!!!

Oh well. I have this nagging little thought floating in my head that I've read about something similar and it turned out to be Windows attempting to do something and having to wait until the operation timed out.

Have you checked your event log to see if there's anything noted there?

ISATAP is part of the IPv6 network stack. You might try turning off IPv6 support to see if that's really what's involved. You can do this as follows:

Start -> Control Panel -> Network and Sharing Center
Click the "Change Adapter Settings" in the left pane
Right-click on the network adapter and select "Properties"
Uncheck the "Internet Protocol Version 6" checkbox and click "OK"

If that speeds things up, then you might want to try re-enabling IPv6 and then resetting the protocol stack by typing the following into a Command Prompt window (will require a reboot):

netsh int ipv6 reset reset.log

ISATAP is a tunneling protocol to allow IPv6 networking through an IPv4 network. So that message probably has nothing to do with drivers and is just indicating that the tunneling protocol has been successfully initialized.

If that's not what's causing your delays then I'm afraid I'm out of suggestions...