Cashing in my CASM for an MMath on 30th apr

The university has decided that a maths fourth year is now officially equivalent to a taught masters, and allowed people who graduated from it to graduate retrospectively with an MMath, even though it generally regards any degree other than a Bachelor of Arts[1] to be a bizarre newfangled fad :)

The first available date is Sat 30th Apr (the Saturday of the royal wedding weekend), and the maths building and Trinity have both decided to put on a lunch or some talks.

And after some procrastination, I'm going to apply to go, as are a couple of other friends (as atreic suggested ages ago). If anyone else did part three and wants the letters after their name to have "maths" in, you may not be quite too late to apply (although Trinity says, by the 12th at the latest, and I assume I was too late already by the time I got round to it).

Links:

http://www.trin.cam.ac.uk/index.php?pageid=1051
http://www.maths.cam.ac.uk/postgrad/mathiii/retrospective/

Dying computer

My laptop has recently had problems starting up. It starts, but if you run more than one or two programs, they stop responding, in a fashion that makes me think of a computer out of memory.

I'm embarrassed because I'm a professional programmer, and yet I don't know everything about some obvious things like dealing with a normal home computer.

I'm buying a new laptop anyway, as this is quite old, but it would make sense to make it usable as well if I can.

What is most likely? The obvious suspects seem to be:

* Physical fault in memory or motherboard
* Hard disk too full or too fragmented
* Rootkit or other evil (I have AVG 2011, but I don't know if it woudl find everything)
* Accumulation of too much non-spyware crap that's installed and runs on startup

How can I most easily tell?