Well i had no idea where to post this, and i really wanted some opinions and whatever i can get out of anyone to help me figure this problem out.  I normally never post anything but this has driven me to the point where i thought it wouldn't hurt to try on here and see what any of you have to say.  I recently bought a new GPU for my old system.  Its around 3 years old, i built this rig back in September of 2005. Oh and i bought a XFX Geforce 9800GTX which has led me to be frustrated into hell. My specs as follows:
 
AMD Athlon 64-bit 3500+ 2.2GHZ venice core
MSI k8N Neo4/Sli nforce 4 sli chipset
Corsair Pro series DDR-3200 2Gigs
PSU- 550watt Ultra Infinity( Thats what i had in it and had problems, switched to a Cooler Master Real Power Pro series 1,000 watt and the problems varied from game to game)
EVGA 6600GT 128mb's - that was my old card
Seagate 120gig's 7200rpm
Win XP 32-bit(Been running this PC for almost 3 years without a format just yet)
GPU Idles at around 60 and gets as high as 66-70c  CPU temp is around 44c and system temp around 42c
 
 
Well when i first got the card, it seemed as if it was running fine till i ran World Of Warcraft, NFS:Most wanted, and Kane's wrath.  I had problems in the games, i either got a frozen screen and had to ctrl+alt+delete and end program, or i had to reboot.  If i lowered the settings it would kind of work but i would still glitch or lag of some sort and possibly freeze.  Doesn't seem right with the amount of power this card has.  As well before i go any further, for some crazy reason i like installing nvidia.com's latest drivers, but for some reason when i install whether it be the newest, older, or just around between them kind of new drivers my PC loads XP and then hangs.  I never get to the welcome screen.  But with the software drivers that came with the XFX cd which are drivers 174.40 the card works fine with those.  Is that strange?  I ran Driver cleaner, still didn't work.  So i said screw it i went and got the cooler master PSU.  My World of warcraft is fixed and works great, a few hiccups here and there but not enough to bother me, but then kanes wrath n NFS most wanted still nothing.  For some reason when i have anti-lansing on at 8x preferably kane's wrath, the game freezes.  I actually got it to freeze and give me a blue screen of death.  It said the device wasn't able to draw a operation, or that i needed to update my drivers.  So i ended up trying again different drivers, and still nothing so i reinstalled the 174.40 and now Kane's wrath works(mind you before i did the driver testing again i had uninstalled and reinstalled kanes wrath and that did not work either) Oh and Tiberium wars though works perfectly with 8x anti-lansing on, this is when kane's wrath didn't work but of course now it works.  I have yet to try NFS: Most wanted again.  But i noticed since the beginning that my CnC Generals Zero hour glitches and lags hardcore as well to the point where it freeze's, never did that with old GPU.  Have yet to know whats wrong with that game, considering that game has nothing to do with anti-lansing on, i might have to reinstall that game as well maybe it will fix it, not 2 sure.  I still have around two weeks before my deadline to getting a refund for this card from newegg.com.  Let me just say one last thing my system ran perfect with my Geforce 6600GT, my system was a bit slow before, but definitely not while playing games. Any idea's on what i should do? Something, a thought? idea?  
Thanks greatly appreciate anyones help on this XD

Hate to state the obvious, but have you checked for patches/updates for the games you are having problems with? Also, have you loaded the latest chipset drivers etc for your board?

I'd agree with patches on the games.
 
Just to add on, check for background programs to make sure nothing is bothering the CPU resources.  Have you noticed if your CPU isn't actual idling when it should be?

 
The games part yes, i make sure every game has the latest patch, considering that CnC Generals zero hour is quite old its patched.  The 3 games i am having problems with are all patched to the latest.  As for my chipset drivers i am uncertain, i don't think i have ever updated those once.   I blame it on lack of experience in updating  chipset drivers.  Also my board is quite strange i had bought it 3 months before MSI discontinued it, not sure why they did that.  But the only thing close to what i have would be the platinum series one.  Would those drivers work as well for it?  Thanks for your guys input, i appreciate anyone's help.

 
 
Well since its been almost 3 years since i have formatted it has taken a long while to get into windows.  But that's kind of normal, as for the idling part the cpu usage varies from 2% to 5%.  I've had my eye on that and it may seem as if something in the beginning slows my PC down to where it takes a bit longer before i can click anything on the desktop.  But i always make sure my cpu usage idles around 0%-2% before i go into a game.  Not sure if i've had this problem for that long.  Thanks again

Only other thing to try perhaps, is the actual nvidia (nforce 4) drivers for your chipset on the Mb.  Perhaps that might help.
 
Nvidia drivers
 

Thanks Grimmy, i guess that's the only thing to try out.  Other then that if that doesn't work i am pretty much screwed. But thanks for your help.

ill be honest with you, i know reformatting is a pain, but i reformat every year and a half or so, which i know is overkill but; i find that windows has a half life, and after each increment it just get worse, as drivers get fragmented and scattered and ans harware upgrade coe and go. there is nothing like a clean install. Your issues does sound like a software issue so unless you've found a fix...
 
And it would allow you to upgrade to vista if you so wish to, to make use of DX10 support that your card has and it would run fine on your system.
 
also while im here you are aware that your CPU makes a huge bottleneck on your system when it wielding that GPU, especially in the games you are playing like CnC. higher end duel core athlons are cheap now maybe an upgrade is in order?
 
hope some of this help, and feel to post any time even if you think it's dumb ;A

Honestly if you had 1 more GIG, i would even recommend (if you intend to reinstall), VISTA 64 Bits.  
2 Gig is not bad but 3 Gig minimum. Sledgehammer and Venice Cores with Vista 64 bits slapped on them run pretty great.
You would be surprised.
 
As for the rest, update chipset drivers and you would be fine i guess.

 
 
Well i was planning on getting Vista in the long run, the card was actually for a future build.  I was just testing it out till i had all the other hardware for my future rig.  I would like to try vista but as of right now all i have on me is Win Xp 64 which i have yet to ever install, though i do plan on formatting in a day to Win 64 with a fresh install of all the latest drivers.  I also RMA'd my card so i have my 6600GT back in and everything is back to normal now.  I was thinking of getting another 2gigs honestly, since prices are quite low for DDR even for DDR2.  Someone always told me that having 2gigs would be unstable, and now i have 2gigs n it runs great.  If i got 3gigs taking up 3 slots won't that create some sort of error.  I'm trying to find memory with the same timings as the ones i have installed.  If i install another memory module 1 or 2 and they have different timings then my other memory that won't create a problem will it?  And thanks for your input Radnor greatly appreciate it  
 

From what ive tested in similar machines they run pretty great with 3 or more Gigabytes. Vista 64x SP1 can be pretty stable and very fast if you have the right rig. If you have DDR2, well buy 2 more. they are cheap, and DDR2 boards aren't gonna vanish overnight. If you have DDR400, well, that is a different ballgame. Let me see if i can do it by memory (im working atm).

Run services.msc.

- Disable Superfetch (it will open a DOS CMD, close it and restart the PC)
- Disable UAC ( User Acess Control )
- Disable Windows Defender ( doesnt do nothing really, just to piss people off)
- Check the rest of the services to see if you can disable more crap. 71 processes with a clean install its ridiculous.
- There are more crap, i just don't remember right now, sorry.

Disabling Windows Vista Indexing (copy/paste , my work pc has XP) :

Run Services (just type Services at the Start Search bar), right click on the Windows Search service and select Properties. Then choose Disabled for the start type. Afterwards, you have to stop this service by right clicking on it and selecting Stop.
Personal note: Indexing service is always Indexing god-knows-what. Take it down fast !!!

Tinkering Virtual memory in Vista 64x

Ill paste a link, so you can take a peek how too. With 3GB of ram you can reduce it a lot to 512mb. Virtual memory is only good to page new process that CAN take ALOT of memory, but they don't. Imagine you run wow. Firstly Wow is assigned to the Virtual Memory has having a possible 2GB max paged, but in reality is taking only a 200mb of ram. With 3-4Gb most apps tend to skip this part increasing load/alt+tabbing times. You really notice the difference. The link i am going to paste tells you to increase it, but hey, tinker a bit, a check what is faster. If you have 3-4Gb take it down, if you have less, well, tinker a bit.

http://spiceminesofkessel.com/2007 [...] -in-vista/

I Hope i helped.

PS: After you disabled the crap out of Vista, and find out that reducing Virtual memory to a minimum really speeds up the PC, don't get scared, if hes eating 1GB or more with a clean install. It is normal.