How do I update QuickTime?
I can't watch certain videos on my computer, and it's saying that I need to update my QuickTime but I have no idea how to.
Click on the "Apple icon" in the upper left corner of your destop, and then click on "Software Update". Your system will connect to the Apple Servers and scan your Apple Applications, including Quicktime, to find all available Updates for your Apps and will then offer to install them for you.
I might add here, what file format are the particular videos you want to watch in, because there are many video file formats that Quicktime is never able to play?. In that case I would suggest you download and install the excellent and Free video player VLC: