Command and Conquer Generals Zero Hour "Fatal Error"

Hey you knowlegable lot, my mate has Comand and Conquer Zero Hour his specs more than cover the minimum for the game ( i even upgraded his ram and graphics card from my spares scattered around)
he has Pentium P4 2.4Ghz, Nvidia FX5700, 512Mb Ram
No internet connection (i do all the updates for him through my pc on a regular basis ;networked
This is gonna be 2 questions :-
1) how come from a fresh install of the game it runs perfectly fine for a few days then all of a sudden if he exits the game it restarts his pc
Then if he trys to run the game again it comes up with a "standard" warning that a "FATAL ERROR" has occured and that the game cannot run due to hardware problems, "The cause of which could be an overheated component or you do not have enough ram in your system or another hardware related problem occured during the initialisation of this game"
I am completely baffled by this as his OS is up to date (win XP Home), he has DX9.0c, the latest game patch installed etc.. game.exe does cause an error in his applications log but the crap it says after doesnt make any sense to me and im not completely dumb with pc's.
2) i have EXACTLY the same HD as him, the Maxtor 6Y080L0 80 GB yet i have noticed that his seems to suffer terrible performance regarding reading and writing speed
for example we both have a dvd RW drive capable of reading normal cds at max of 48X so when we both installed the ZH game i expected at least both our pcs to finish at around the same time, however, my install of the game was done in a few minutes while is was taking absolutle AGES to even get through the "initialising the installer files" and even though his drive light was on continuously the game took at least 12-15 minutes to install, its even the same when he un-installs it, it takes ****ing AGES!!, mine takes litterally seconds you can see my specs in my public profile.
his HD has a bigger C: partition than mine, and he has no rubbish on his drive as he only wants it for games, there no viri, spayware on it its a perfectly clean and defragged system and compared to the technology in mine, its newer!!
please can anyone at all shed any lite on this problem, im willing to show you anything screen wise if you ask for it, il do whatever it takes (short of selling my body lol) to get this mofo working for him thankyou in advance

 

could be a cheapo generic drive that cant properly read cds/dvds.

 

my brother said it could be something to do with IDE controller on mother board im guessing what he means is, get a new mobo. well its up to my mate hes paying for it, it was a pre built system from a catalogue, personally i would send it back and all the money hes saving would buy him parts for a system 10 times better, but thats just my opinion...

 

could be that too, maybe he never installed VIA/Nvidia mobo drivers.

 

the nvidia drivers are installed (latest) and a program from the intel website checked his CPU and reported it working correctly now something else cropped up and made me go at it. 3DMark reports his cpu as having hyperthreading but not enabled, yet the intel official chip recogniser says his cpu does not have hyperthreading im going dizzy now. Also i installed him a program called Tweak Now Powerpack, and only enabled 2 things on it, one for "enable DMA 66 support on intel chipset" and the other for "improve core system performance" ( it forces Executive files to remain in ram rather than going to virtual memory ) and although the game still doesnt run any faster the hardware warning has gone and it doesnt restart his pc when he quits the game so im wondering why this had an effect