I have actually done this before. I used Partition magic then. I didn't use the bloated windows version, though. If you look in a Partition Magic directory, there is a DOS-text based version that will allow you to resize your partitions without losing anything. Sorry, I forgot the filename. Procedure: Make a bootable dos floppy disk. Copy partition magic files to disk. Start Partition Magic from floppy and resize. Guess the winversion will work fine also.
IMPORTANT: Also, on dual-boot systems, Redhat won't start if it is not at the begining of you hard drive. Partition thusly:
"/boot" is your 1st Partition about 80MB It will point to the Linux Install.
"/mnt/windows" second partition containing windows
"/swap" is your swap partition I use a 1000MB size
"/" is the root of your linux installation remainder of hdd space
*** No quotes, of course
Set up your partitions like this an you will be fine.
**It would probably be easier to back up important data files and start clean. Good chance to corrupt your master boot record.
IF YOU CORRUPT Your MBR, get a bootable DOS diskette, with fdisk.exe on it, boot using the floppy, and type "fdisk /mbr" (no quotes) This will fix your MBR and you can start over.