I  was stupid enough not to make a backup of my win98 floppy rescue
disk before attempting to enable edlin (usage of which needs setver in
the config.sys). Now the rescue disk is bad, but fortunately win98
loads from C:
My question is how do you make another rescue disk?
If anybody knows, I would also appreciate to find out how to enable
Edlin (of DOS 5.0)to work without messing something else up with a
wrong kind of Setver.

You can get another disk from www.bootdisk.com.I can't imagine why you
need edlin,the bootdisk will have the "edit" command which will handle
all your word processing needs.Download the file to your hard
drive,click on it and it will ask you to insert a floppy disk,don't
download directly to your A drive or it won't work.

That's www.bootdisk.com

Well go to control panel then opem add remove programs , 
 then click on the tab , startup disk , then place a floopy in the
drive and press the create disk button.