after booting the LinuxOS i m unable to enter in either text mode or Graphical mode
How so? In what way are you prevented from performing the action you describe as "enter"? More to the point, what is this action? Do you mean "log in"? Or do you refer to executing commands on the console?
i.e., for the first time linux will not boot
Your first paragraph states that you encounter a problem after
booting. Now you say you cannot boot. Which is it?
Linux flavor is Fedora Core 6
FC6 is legacy
, you can expect problems.
So lets see if I understand properly:
You have a dual-boot computer.
You switch the computer on.
At the GRUB menu, you select Windows PWN^WXP instead of fedora
... windows boots just fine.
... you shut windows down (by which method?)
... you boot the computer (restart?)
... select fedora
... ... fedora boots properly.
But if you: get to the grub menu, and select fedora core 6.
... fedora core 6 starts to boot (what happens?)
If fedora cannot load on a cold boot, but will on a soft reboot (from another OS), then there may be some BIOS controlled power management interfering. Perhaps the BIOS puts everything it controls to sleep when the computer shuts down? Fedora lacks the software to wake them up. When Windows boots, it wakes everything up. When you "restart" the computer never actually powers off so the BIOS never tells it all to sleep.
Enter the BIOS and disable anything you find beyond basic ACPI functions. Look through all the menus.