BSOD due to Inspect.sys

I have been using this PC for a while now (6 months+). From past one month, I am getting BSODs with different messages. I ahve tried doing a clean instal, reinstall and even repair instals but am not able to figure out why I am getting so many BSOD.
Here are system specs

Processor:
Name         Intel Core 2 Quad Q9300
Codename      Yorkfield
Specification      Intel® Core(tm)2 Quad CPU Q9300 [at] 2.50GHz
Package         Socket 775 LGA (platform ID = 4h)
CPUID         6.7.7
Extended CPUID      6.17
Core Stepping      M1
Technology      45 nm

MotherBoard : P5Q Deluxe
Ram 1 GB(600mhz) + 2 Gb Trascend(800 Mhz)

Hard disks
1. 500GB Seagate(SATA Port)
2. 350Gb Seagate( SATA Port)
3. 250 GB Seagate ( IDE)

Nvidia GEForce 7300GS

BSODs

I am going to upload as many crash dumps as possible. Most of the crashdumps says inspect.sys, tcpip.sys, TDI.sys Memory Pool, and a few more are corrupt.It gives a different one each time.

The crash may happen at any time, while i watch avideo or just work on firefox or when my system is just downloading via bitlord.It is quite unpredictable .
I hope you can check and tell me what is wrong with my system and how to correct it.

Thanks
Hari