It's event viewer, Tom. Start / Run / eventvwr .
I agree with the others in that most of the time, the driver_IRQL_not_less_or_equal error is hardware-related (usually RAM). However, in this particular case, the probability of a hardware problem is perhaps not quite as high as usual.
I say this because afd.sys is part of the TCP/IP stack. Specifically, it's part of Winsock. (In laymen's terms, it's part of the software that allows your computer to connect to a network or the Internet.)
Many, many things can cause problems with the TCP/IP stack, including network card drivers, virus scanners (which often install virtual devices), firewalls, viruses, spyware, old LSPs, some BHOs, etc. So I'm less certain that the error is truly caused by bad hardware when a TCP/IP component is involved.
In addition to the advice already received, I suggest you run a memory test. Typically this is done with a bootable utility that simply runs the memory through all sorts of tests. I like to let the tests run for several hours, even though they are repetitive, because sometimes physical RAM errors only occur once the RAM is hot. There are dozens of these tests out there; the one I use is included on pretty much any bootable Linux version out there. You would have to create a bootable floppy or CD to use any of them. (I can mail you one, if you like.)
If the memory test works out okay, I would use something like HijackThis to look closely for LSPs, BHOs, and other objects that might be causing issues, as well as check the registry for remnants of previously installed security software that may not have properly uninstalled. This might be something you'd want a pro to do, however.
I also would look at whatever security software you're using now, to see if there are any known issues. Possibly uninstalling and reinstalling the security software may solve the problem.
As a last resort, I would uninstall everything related to networking and reinstall it again to rebuild the entire TCP/IP stack.
Failing at all of the above, I would call George, Myron, Floyd, or one of the other tech guys in Bangalore and try to get the laptop replaced. If it's not RAM and it's not software, then it's either the processor or something on the motherboard.
-Rich