How do I tell MEPIS to let Windows boot by default? I can't find such a command in the control panel.

A very bad idea, indeed. You're just trying to make it easy not to use Linux.

Nevertheless, if you're determined to use Windows instead, look at /boot/grub/menu.lst for a line like:

default 0

and change it to ... default 1

Open up /boot/grub/menu.lst as root.

Change the default 0 to whichever one the windows entry happens to be. As Mepis usually has a couple of entries of it's own before the windows entry, you'll have to count them. If windows is the 3rd entry in the list you change default to 2 (grub starts counting from 0)

[QUOTE=rickh]A very bad idea, indeed. You're just trying to make it easy not to use Linux.

Now just a minute...you have made an undue assumption, and you know what they say about "assume." I'm still at a point where although I can do many basic things in Linux, I can't tell you much about why anything works the way it does.

Another option you might find useful is to change the default to "default=saved". This makes it so that GRUB will default to whatever option was chosen last time. I like this because it makes installing stuff on Windows less annoying (the reboot party, you know), while also making it so that the 90% of the time I'm using Linux I simply reboot into Linux.

My /boot/grub/menu.lst does not have a default entry at all. It reads as follows

timeout 15
color cyan/blue white/blue
foreground ffffff
background 0639a1

gfxmenu /boot/grub/message

title MEPIS at hda6, kernel 2.6.15-26-386
root (hd0,5)
kernel /boot/vmlinuz-2.6.15-26-386 root=/dev/hda6 nomce quiet vga=791
boot

title Windows at hda1
rootnoverify (hd0,0)
chainloader +1

title MEMTEST
kernel /boot/memtest86+.bin


To make Windows the default I changed the order of the paragraphs so the file reads

timeout 15
color cyan/blue white/blue
foreground ffffff
background 0639a1

gfxmenu /boot/grub/message

title Windows at hda1
rootnoverify (hd0,0)
chainloader +1

title MEPIS at hda6, kernel 2.6.15-26-386
root (hd0,5)
kernel /boot/vmlinuz-2.6.15-26-386 root=/dev/hda6 nomce quiet vga=791
boot

title MEMTEST
kernel /boot/memtest86+.bin

This worked for me.

Yes, that works because in the absence of a "default x" line, the entry corresponding to 0 is used as the default.