Work around Mozilla / Firefox Slow Restore in Windows

Mozilla in Windows has a tendency to get paged out to disk way to fast. So, if you happen to leave Mozilla (not closing it!), after a few minutes of using another application, you might find that it is very slow to switch to / maximize the Moz web browser. There is a preferences hack that will work around the problem for most users (including me).

It's well described here: http://windowssecrets.com/comp/041202/

Important part quoted here:

Fortunately, there's a hidden setting that can accomplish the restoration of Firefox windows much more quickly:

Step 1. Use about:config to create a new, Boolean value. Type or paste the following string into the dialog box that appears:

config.trim_on_minimize

Step 2. Click OK to close the dialog box. Change the value from "true" to "false" and restart Firefox.

This doesn't piggishly retain all of the RAM that Firefox has claimed. If Windows needs more RAM to devote to another application, Windows can take it. What the setting does is prevent Firefox from giving up most of its RAM until the memory is actually required elsewhere.

And a long debate in bugzilla about whether this is a temporary workaround or a long term fix is here: https://bugzilla.mozilla.org/show_bug.cgi?id=76831#c329

Bottom line, don't expect this setting to become the default one anytime soon.