Software to check bottleneck?

First, we need to know your system specs.

Bottlenecking is more of a theory. It is the slowest part of the PC, that impacts performance of a newer, better part. i.e. Using 8800GTX with a Celeron. Usually the biggest bottleneck is the hard drive, but many say it's the CPU.

Also, there are no programs. You can use 3DMark to see the CPU score, and the 3D score, but the benchmark isn't that great in telling real gaming performance.

Here's my spec.. It's pretty old.
Pentium 4 Northwood 3.06Ghz
Intel D8OEMV2 Motherboard, Chipset Intel i850e
RDRAM 1024MB 530Mhz
Seagate Barracuda 7200.7 Plus: ST3160023A ATA100 7200rpm
Getting Maxtor 200GB L01P200 8mb cache, ATA 100 7200rpm (from Staples Black Friday)
Nvida 6600GT AGP 128mb
Mother Board doesn't take SATA so going SATA would mean adding a PCI controller

thats doesnt look anything bottlenecking . let me tell you my bottleneck - Um using GTX 650 TI with old crappy core 2 DUO @ 1.8 GHZ