Picture is 1200dpi and would like to change it but resize shows feature locked- how can I do this as the size makes my computer run slow.

There are some lock icons on the left. One of the three options has to be locked, you can change the lock by clicking on the icons.

thanks - that worked - the locks are hard to see open or closed- for some reason it remains a 13 meg file and runs very slow I don't know why this file is so hard to deal with.
Thanks for the great program

You only get a size reduction if you decrease the amount of pixels.

I thought going from 1200 dpi to 100dpi would do this
the pic is 1200 x1200 so it is not to big with maybe 10 layers now but runs really slow-
is there another way to make it a smaller file size?

A ten layer 1200x1200 pixel picture shouldn't make Krita sweat at all, not even on somewhat older hardware. Could you share the .kra file with us?

http://www.4shared.com/folder/Au06D7QV/_online.html

jeant.kra is the larger one