i have a PC on which i installed windows xp when it was released in 2001 also a toshiba celeron 550Mhz with Xp. I have never re formatted and reinstalled windows ever. except for adding the occational hardware upgrade (soundcard etc.) and software installation (Windows and driver updates etc.) . My desktop uses an audiotrak 8in 8out card and 4 SCSI 15000 rpm 250GB HDD. one 80GB IDE for system files and software installation. On my desktop i run sonar 3 on my laptop sonar 1.3

and reason 2.5 on both as well as Adobe audition 2 and various plugins and softsynths. I use many sound modules and synths/samplers so i dont depend on soft synths. On my laptop i once used 16 audio tracks, 3 inserts fx per track and 2 send fx for master. no jitter or any dropouts whatsoever (And that is sonar 1.3)
I have had nothing but happiness and bliss. I have recorded 4 commercially released Cd's on them. Even music for radio and tv ads. Never had any problems,
My secret? Use your Studio PC as a Studio PC. Forget Games, Internet, even doing your day to day office work on it. You cannot use your lamborghini to move your furniture or take your family to dinner in your truck.

Uninstall all plugins you dont intend to use. Research, and use only the ones you need to get the job done. If you are serious about your job, be serious about your tools.
I have now just purchased a new machine. AMD dual core 6000+, 4gb 667 ram, and 4 SATA 300gb HDD, Running vista ultimate, Sonar 6, Reason 3.0 and again adobe audition. This time i also added fruity loops 7, bfd and MOTU ethno instruments. I assembled the PC myself and purchased the parts for... 1000 us dollars. It is liquid cooled so its quiet as a mouse. Not 64bit yet, but will as soon as more support becomes availble. a yamaha 01x controller etc. So far...it is blazing!!!!!!!! faster and more powerfull than anything i have ever used. yet to experience crashes and hickups. Installation was a breeze.
My mate has a mac. G4 running Pro tools. I love it! it looks nice and is really quiet. but he has a problem. he has a digi001 and os9. wants to upgrade to osx for new protools but cant as OSX does not support digi001. So now he has to go and buy new soundcard.

It is this kind of hickups that a commercial studio just cannot afford. And its the only thing that puts me off MAC. other than that...tools are tools, it is only what YOU can make them do, that makes the difference.
My advice...buy what you can afford. let it make money for you and then upgrade as you go along.
hope it helps and i'm not too late.
Ok!!!!!....Now i have all the equipment....if i can just learn to play them.
Ok!!!!!....Now i have all the equipment....if i can just learn to play them.