I have had a similar experience just recently involving a newly upgraded system and medieval: total war1 (the first mtw, as I'm not convinced that mtw2 is worth buying in it's current state, until it is suitably patched/goes gold, etc). I bought this computer a year ago (athlon 3500+ single core, 2gb ram and geforce 7800gt) and over the course of that year, configured the system until it was to my liking and ran well. At the start of this year (6 weeks ago), I then had the not-so-bright idea to drop the computer in to the place from where I bought it, for a processor upgrade (4800+ dual core). They told me that they were having some problems with it and needed to format the hard drive (eventually and for some strange reason, they replaced the drive, under warranty). However, each time I got the computer back from them, it died on me within 1 or 2 days of normal use (and often within just a few hours). By 'normal use', I mean connecting to internet, d/loading the very many windows xp updates and playing 1 or 2 games. The game that caused the system most problems was medieval:total war1, which kept causing the system to crash and reboot itself (equivalent to the blue screen of death). I returned the computer no less than 5 times, until they finally got it right. By 'right', I mean until I was able to play medieval:total war1 without this causing the whole computer to crash - the actual game did crash on me many times, but I wasn't too concerned with that, as long as it didn't crash the computer with it! I've now been using the system for a few evenings, 5 or 6 hours each evening, doing various things with it (installations including reinstalling windows xp, configuration, internet and gaming) and it hasn't crashed on me once, for which I am eternally grateful. The computer place eventually concluded that it was the new processor that was causing the problems and they simply replaced it with a new one. However this was not before they had also replaced the motherboard (for a better one), a larger case to fit it in, the sound card and hard drive!
Each time the computer place gave it back to me (5 times over the course of 6 weeks) they assured me that they had tested it to their satisfaction, using various testing software such as 3dmark06, etc. However, the best test of the system I found was to try installing and playing medieval:total war, since mtw is a most tempermental game at the best of times and trying to run it on anything less than an optimal operating system will cause problems (either the game will crash frequently or it will cause the entire computer to lock up/crash). When I finally got new computer back for the fifth time, I therefore made it a priority to test the system using mtw (in campaign mode, playing for at least a few hours involving both the main map and real time battles), firstly to check that the computer was without fault, and secondly to configure the system until it could run mtw without causing the game to crash. This second one involved going into msconfig and disabling many start up items that could affect the running of the game. Once I had mtw running and playing for a few hours without crashing (in campaign mode), I then set about continuing to install various other software and configuring the system, each time testing the system with mtw. If I made a change to the system, or installed some software which then caused mtw to crash, I would know what the cause was. The point I'm trying to make is that just because your system can run sisandra or any other 'testing' software without causing the system to crash or lock up, don't take that as a sign that your system is all A-ok. The best test I have found is mtw (and it is also more fun!). If the computer can run mtw without crashes (either in the game or the entire system), then you know you have a rock-solid system. If you have mtw1 gold, I would use that, rather than mtw2, which is still under development and has many known (and unknown!) issues. Sorry this is such a long-winded post, but I'm currently sitting here bored at work with little else better to do with my time [edit: at least I was when I actually wrote this 7 hours ago - just had this late opportunity to post it!] If your interested, in my mtw campaign I'm playing england and I've just been attacked by france in 3 provinces, which is going to make for an exciting evening's play.
Facebook
Twitter
Instagram