Hai,

My RHL 4 os correpted (not booting),

Now I need to install Both winxp & Redhat Linux 4,

tell me What is the Best & Fast I can do?

So, how it seems, there isn't any working OS on your PC anymore. But to help you, I need some information:
- how big is your hd
- how are the partitions
- which OSs are installed
- do you know you use grub or lilo
- is there any data to be saved

yes,

I have existing linux (ext2) partations,

that can be erase, no data,

now i need to install both OS

how big is your hd 500Gb
- how are the partitions ex2 partitions
- which OSs are installed RHC4
- do you know you use grub or lilo yes I know
- is there any data to be saved No data

First partition your disk
install windows on the first partition, then install linux.
Use the bootloader from linux

So, then take your Xp cd, boot it and (i just think you have ~100GB hd)delete all the partitions. then make a 20GB partition for xp, format it with ntfs and go on installing. after installing it, open computer administration (search it - i'm german and don't know it were to find it in an eng xp) Then open disk managment and you should see your hd. there should be a 20gb ntfs partitions and 80gb free. if you want, make some extra partitions, just leave ~10-20gb for rhl. reboot your pc and install rhl. it schould automatically detect win and after it is installed you should be able to boot both rhl and xp.

oops i havn't seen that bout your hd sorry

when I try to install winxp,

It will not show me the space..

I can not able to create or modify the existing linux partitions..

then what is the best I can do?

Download a live cd, and partition the drive.
http://gparted.sourceforge.net/livecd.php

Can we have the option to remove all partitions (both ext2 & Fat) using bootable cd of linux rhc4?

Yes, I think it should be possible. Try it. (it doesn't matter when the hd is deleted, so...)

do you mean Redhat Enterprise linux 4? or Red Hat Linux 4?

If it's the latter, that is VERY old, you may think about upgrading to a more current distro.

well, i have never tried out rhl, but if i were you, i would take openSUSE Get it!