: i can't seem to close the shut off valve to my upstairs cold water. the stem will not budge in either direction. this cut off valve is in a home i bought new 10 years ago and has never been used. is there anything i can do that will free up the stem so i can use this cut off valve?. would backing off the packing nut a little help? are lubricants any good to use? if i do free it up do i run the risk of the cut off valve leaking afterwards?... if all else fails should i use the main cut off valve inside my house or the one outside of my house from the main?..... THANKS.

Don,
Assuming that the plumber didn't solder shut the valve, you may be able to disassemble the valve by un-threading the upper portion from the main body.
Terry