If you hard reboot (power button) does it let you go on by the welcome screen the 2nd time around? Is there a similarity between what you are experiencing & what I have going on?
My laptop for quite a long time now has had the habit of hanging every time I try to access my dialup internet connection
for the first time of the day only - it hangs, I do a hard reboot, then I'm good to go for the rest of the day.
I recently for some unremembered reason set my computer up with user accts (there was just me and guest before) and require a windows logon. I think it was because I was going to leave it running overnight at work with pcanywhere. I noticed that whenever my machine booted to the welcome screen where you'd normally see the users and choose one, the machine was locking & I'd have to do a hard reboot - just like it does with the dialup network access. I've gone back to disabling user logon requirements, and no more problem.
I probably need to reinstall my OS but I just haven't been brave enough to try it with xp. I am now wondering if there is something corrupt in the network protocols or drivers or something that causes this.