Just a quick update ; < " i found a solid and practical solution " >
After trying out comodo internet suite , using its defense module , one can set custom protection settings for each program.
I was able to immunize firefox to external windows message pumps from other processes and it worked flawlessly.
No application could make firefox launch websites "ie: clicking menu::about and clicking their website link doesn't open websites anymore, or any other application specific auto link launches, "like those sites that pop up after new installation or uninstallation" perfect !
-also there is a white list for the applications to launch links unaffected , "if you have set a general block that is"
A quick tutorial on how to reach that filter window within comodo is
->main menu ->defense->advanced->computer security policy->"find all applications header entry"->click edit->click "access rights"->add firefox or iexplore exefiles into blocked tab.
these steps immunize that particular application against outer windows message pumps.
There may be other ways to do this , but im perfectly happy with this solution .
Internet explorer and firefox can be immunized against unwanted external actions.
Source: MozillaZine forums
NOTE: In your case, you would need to create a firewall block rule for each actual uninstaller exe (as opposed to the app itself), or else just create a generic block rule that prevents anything from opening your browsers automatically.