Hardisk not detected+BSODs!

[mediator]

Hi friends.....I've been experiencing some hardware problems these days.

Present Configuration
1. 160Gb WD HDD + 80 GB seagate hdd
2. 512 MB ram
3. 2.4 Ghz processor
3. Nvidia 5200 graphic card!

Problem :
1. Now whenever I am on the system........it sometimes shows "Kernel page error" and then the system hangs in Xp. When I reboot it shows System disk failure error!
The same is case with Fedora 5. It hangs and followed by same error.
2. Playing games like Quake 3 it shows all kind of blue screens!

Now because of the problem I changed the IDE connectors and CMOS battery. But still the error persists!

Also What will be the price for upgradation for
1. RAM : 1 GB
2. Processor Duo core : suggest
3. Motherboard : suggest
4. Cabinet : suggest
Suggest the best of kinds for above with their prices under Budget = 20 K (max).

Help!

[kalpik]

99.9% its a faulty RAM module.

[mediator]

Thanx for reply.........but u sure?........I mean have u experienced it ? And what abt hardisk detection is it RAM based toooo?

[mediator]

Hey....I observed when I put another fan inside...the BSODs reduced greatly!! Even mah bro's not complaining nowadays. Can it be a heating problem??
Neways can u suggest some good cheap cooling solutions??