Cannot drag new buttons onto toolbar

I'm in customize mode, looking at All Commands, and I want to drag a few new buttons up to my toolbar.
It works on the machine where I work. But not on my home computer!
The toolbar is not locked,
So what else can be happening?

Thanks

It's likely something has broken something in your registry which Opus depends on.

See the FAQ, Drag & Drop does not work for files or when customizing toolbars, for the likely fix.

thank you sir!