" i was able to install Red Hat Linux 7.2 as well. but Linux crashes
soon after the kernel is booted."
"Soon after" you wrote.. Try to start a 'from scratch installation' again
and WAIT after the install kernel has been loaded ... and do nothing!
If your system will hang after say 5-10 min without any external activity
it seems to be a serious problem. But, make sure you've deactivated any
APM/power saving settings in your computer BIOS for this test.
Try to do it at first.