when i install linux on my hard disk , it installs fine but fails to boot the kernel . i tried to
install windows too later on , but it works fine but after restart fails to boot and monitor is
switched off when it tries to boot .... can any1 help me how to fix this or tell me ehat could
be the possible problem

Hello,

the info you gave is not so clear but it seems like your boot record is currupted or something wrong with your PC hardware.
Try to run knoppix so you'll know if there's something wrong with your hardware.
If your hardware is alright then it's surely the boot record so you must try to fix it.
Mandrake Linux 10.1 Community Instalation CD has an option to fix the boot record since I dont know what distro you're using.
There are surely other tools to fix that but if you prefer you can delete all partitions and reinstall the systems again.
Usualy when I have a dual boot I install Windows before Linux and I advice you to do that also.
Leave enough unpartitioned space for Linux and install your Windows.
Then depending on the distro you're using install your Linux wich will write a LILO boot in the boot record of your main partition.

This should work or else your disk may be damaged at boot record.
In that case I believe you can install LILO boot in other partition rather than main.

Hope it helps.
Good luck

Zaman,
If, as you say, you installed Windows after you put linux on your system, it won't boot. Windows has a deplorable way of thinking it's the only OS on any computer, so it doesn't allow anything else but itself in the MBR. The only way to get around this is to install Windows FIRST, then you can go back and may be able to recover your Linux system by reinstalling LILO, GRUB, etc.
Basically, always remember: Windows has to go on first, then add everything else.
Hope this helps,

jfrey