Operating System
Windows 7 Ultimate 64-bit SP1
CPU
Intel Core 2 Duo E8400 @ 3.00GHz 36 °C
Wolfdale 45nm Technology
RAM
6.00GB Dual-Channel DDR2 @ 333MHz (5-5-5-15)
Motherboard
ECS P43T-A2 (CPU 1) 30 °C
Graphics
DELL E176FP (1280x1024@60Hz)
SyncMaster (1920x1080@60Hz)
1023MB NVIDIA GeForce GTX 550 Ti (Undefined) 52 °C
Storage
465GB SAMSUNG HD502IJ ATA Device (SATA) 33 °C
465GB Western Digital WD My Passport 0740 USB Device (USB (SATA)) 35 °C
Optical Drives
DTSOFT Virtual CdRom Device
TSSTcorp CDDVDW SH-S223F ATA Device
WD Virtual CD 0740 USB Device
Audio
High Definition Audio Device
Replies
If you want to do high end stuff, a computer with a better CPU and more ram would be helpful. You can easily add more ram, but your motherboard is too old to support any current generation CPUs, and it isn't worth upgrading your CPU without swapping the mobo (you'll pay too much for too little of an improvement). Its not worth buying more ram if you're going to swap mobo/cpu, as you'll likely need new ram as well.
A better video card would help too but thats less of a concern than the CPU/RAM.
Nothing crazy, I could do some head sculpts in ZBrush and anything low poly was no problem.
Only when you get to the really high poly stuff like full high poly characters would my RAM max out and my frames start dropping.
Don't let your hardware hold you back, because if you're just beginning it probably won't.
Sculptris is not ZBrush by any means but it's free and if you sculpt with it for a little while you'll get an idea of what your computer can handle
For Polygonal download Blender or even better a student version of Maya (I'm not sure if they still do that though) and do the same, learn how to use it and test your hardware limits.
it's not enough when you are working competitively when your work speed, not your pc is actually important.