try installing dosbox to a diferent location and see if it works then
In vista the editing of dosbox.conf doesn't always happen on the real file, but on copy.

you can see if this is the case by typing

1type autoexec.bat

inside dosbox. See if the lines you want are there.

yeah, that happens with me
It seemed impossible to get around because even when I said "yes" when it asked if I really wanted to open it, really wanted to replace it, really wanted to change, and was really really sure, it still locked me out... and I'm admin!
BUT I got around it: just make a copy of it somewhere else ("copy C:\Program Files\DOSBox\dosbox.conf My Documents" or something in the Vista command prompt), change the copy, copy it back, tell it you're sure, tell it you're sure again, maybe tell it you're sure one more time, and bingo, your file is different, start DOSBox, and your virtual autoexec.bat should be the way you want it

or right-click on DosBox.conf, go to "Security" Tab and modify permissions for write access.

I tried that first and it already wasn't read-only, but I tried it again just now and for some reason it works, I can save it directly.
MORAL: Vista is confusing 😕

Well yeah but permissions are confusing enough by them itself without adding Vista to the equation. 😀

Yikes; still doesn't work.
I first copied the entire program to another folder, no luck.
I then moved just the dosbox.conf file to another location, and used the -conf switch to look for it..no luck

The dosbox.conf IS being read. I know cuz the tail end of the file (in the Autoexec section) I have a program call in there. The program IS called and run, but the capsLock is off (capson.com command ignored).

In Win98/se, the Capson.com caused the program to start in CapsLock-on mode.

Any known fix for this?

does pressing capslock work at all under dosbox on your vista pc ?

OK, I'm an idiot! 😵

I just had an epiphany. I wondered "Why does the c:\capson.com appear in the dosbox.conf file anyway"?

Just realized that years ago when I had this issue on my 98se box, one of you helpful geniuses sent me the capson.com program which was sitting in the root directory of the 98 box.

Solution: Copy CAPSON.COM from the 98 box to the Vista laptop.

Works like a charm. I'm such a dope! Thanks for your attention guys.
Sorry 🙁

I 'heart' DOSBOX.

the standard way to type that is <3
I <3 DOSBox
just letting you know