I'm an AutoCAD and Inventor user myself. Decent processor. Obviously, the more the better...especially in CAD. Has he looked at any workstation cards? This will work alot better than the 7600gs. Or is gaming an issue? Also, i would check into driver support with Vista and CAD. The last thing you want is to be in the middle of a render and have The system lock or fail to premature drivers. I'm not sure about him but that would kind of worry me on Vista. At least for a while. Also, I would stay away from generic power supplies that come with cases ESPECIALLY DURING CAD WORK. You might want to look into a decent name brand ps such as Silverstone, Seasonic, OCZ, PC P&C, Thermaltake. These things mite set him over budget but i would at least try a better power supply.
Workstation cards would push his budget over by like $1k so thats kinda out of the question. The thing is he has to use his work laptop (thats politically incorrect now isnt it? Good.) coz his pc is like 10 years old or more. Its a 333mhz pentium with 92mb RAM. This is his first upgrade like ever and he isnt loaded. So anything better than his laptop is what hes looking for, since he can do his work on that, just. I dont know much about CAD, all I know is he does design stuff for building architecture. I'm not sure if that really falls under CAD even lol.
EDIT: As for the psu, again money is an issue and I'm trying to keep his system low power so that there is no problem with overloading the psu. I believe the psu has 18A 12V since I have that same one in another pc.
Not bad, if he doesn't do much 3D design this should be fine IMO. I'm thinking 2D design drawing in AutoCAD. The biggest hits from my experience are from insufficient memory and slow disk access than the video. For very light users of the 2D stuff I don't even give a graphics card to, mind you I mean people going in and correcting an error the drafter made, and not the drafters themselves.
For the price you probably can't do much better (bigger hard drive maybe? not sure how many files he generates).
I just built myself a pc for the same purposes and I would think about looking into the Quadro or the FireGL lineup of things. They are very well geared towards cad and 3d work. Also, at the moment upgrading to Vista is not advisable for anyone in the content creation (cad 3d etc) sector. It will create far more problems than it is worth unless you want to be playing tech support for your friends dad for the next 6 months before it becomes anywhere near stable for workstation environments and vendors make vista patches and driver updates. A good alternative until then is finding a vendor that has the free upgrade to vista tickets. So buy xp pro 64 bit w/the upgrade ticket for less headaches.
He does 2d and 3d stuff. Like I said before the workstation cards cost too much, and since he currently does stuff on a laptop, the 7600gs should be sufficient. As for the HDD, he was going for a 320gb but changed to a 160gb to save money coz he didnt need the space. Hes using win 98 atm (xp on the laptop tho) so going for vista over xp kinda makes sense as hes going to have to get it eventually anyway. I will see if he can get a good price on an xp version, with the vista upgrade path thing. Btw is that upgrade path for a full retail version of vista or just an oem or upgrade version?
Beware of that mobo, I tried two of them paired with IDE hhd, and I don't know why (maybe the crappy southbridge) it turned everything very slow. Or that two mobos were messed up. But may guys don't complaint. I'd advise you to drop a few more and buy something better. That mobo is good for someone who wants to upgrade to c2d and keep agp card or ddr ram.