How do I use house themes. I bought the My First Laboratory theme but i dont know what to do with it. I thought i had to give it to that house robot but i killed him. What do I do and can i get another house robot ?

Well first off did your house change and now looks that a lab?

If not i think i know what went wrong. you don't need the robot to get the themes. I'm assuming that you picked the lab theme and your house didn't change but when you try to get the themes there is two steps first you have to go to the speech option "tell me about the themes" or something like that. then you pick from the list of themes, and then you have to go to "lets see what you have for sale" then actuality buy it.

If you did the above steps and it still isn't changing then maybe you've got a glitch. so save your game under a different file and then try to buy a different Theme and see if you house changes.

Well that's all i got hope it helped.

That is an add on. Not a theme.

It should appear at the top of the stairs on the balcony in the Megaton house, by the table. Not sure about Tenpenny.

A theme changes your whole layout. Like a Vault 101 theme would have big computers and ceiling lights, etc.