How do i get demo off of ps50c450 plasma - Samsung PN50C490 50" 3D HDTV Plasma TV

Refer its user manual for details.
http://electronicshelponline.blogspot.com/

Use tv remote to enter osd menu. Find set up.
Set location to home not showroom.

The TV is in demo mode. Turn it off via the menu; the instructions would be beneficial here.

Unplug the power
Plug back in
Turn on
You should see initial setup screen
enter language
select home use

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/jason_77a19afa8d604dee

Check your Menu for Demo Mode,make sure in Not Enabled

Read a book instead

Hit the set up button on the TV.
You'll see options to change the language. The last option is to put the TV in "Demo Mode."
Put the TV in Demo mode, when the first screen appears, "Welcome to...." the PIP will disappear.
Hit exit before the screen moves to the "Menu." If you miss it, watch the demo once--it will restart--and hit the exit button the next time you see the "Welcome to" message.

I just did this and it worked for me - i hope it works for you

Hey there..I had a PIP problem for the last 6 weeks and just solved it with this tip. The solution was in front of me all the time.

Hit the set up button on the TV.
You'll see options to change the language. The last option is to put the TV in "Demo Mode."
Put the TV in Demo mode, when the first screen appears, "Welcome to...." the PIP will disappear.
Hit exit before the screen moves to the "Menu." If you miss it, watch the demo once--it will restart--and hit the exit button the next time you see the "Welcome to" message.

I just did this and it worked for me - i hope it works for you

Did you have any luck? My LG is stuck in demo mode too. Menu button doesn't work, and keylock was on as default so I can't use the buttons on the TV itself.

Strange...but i have the exact tv...and I was able to delete the demo..but never had a problem with it popping up every 15 minutes.