MODERATOR, please reject previous commment. This worked for my region 1 disc and my C350 DVD player played it like a piece of cake! I'm not sure if the above arrangement of highlights will work for other regions, but the instructions I found says it will make the player region-free. Different DVD players will have different operations. Press the following keys in succession on the remote control. Select English (or any language) and you can pop in a Region 1 disc immediately. Make sure the DVD has already been removed from the DVD player. Wait 5 seconds then press Power button on player (not remote).
Press Play button (on remote) to save the new highlights. You may want to revert to the original settings when you want to send the device for warranty or if something goes wrong.
** NOTE: I recommend you backup the original highlights in the numbers menu by noting it down on the back of the player's manual or some place safe. Use arrow buttons and Enter button to highlight or unhighlight numbers.
You will get a menu full of numbers.** I don't know what any of the numbers mean but taking clues from instructions available for H1080 DVD players, I highlighted all numbers from 1 to 9. Press Next Chapter (two arrows to right with line). Press Fast Rewind (two arrows to left, no line). (The following buttons are on the remote.) Press Repeat (plain, not A-B). Press Power button on player (not remote) to turn on player. Almost all the new players from Sony are 4K-ready. If you purchase one of these region-free models, there are no worries about your old DVDs being incompatible or the need for two separate video devices. After trying everything I could find, I discovered that this works: All Sony Region-Free Blu-Ray Players are reverse compatible, meaning that they can play Blu-Ray and DVD discs from any region in the world. I have a Samsung DVD-C350 that's locked to region 3, and I wanted to play a region 1 disc. The above instructions could also work for DVD-C350K, DVDC360, DVD-C450 and DVD-C450K since they're in same series. The original comment by the anonymous person is also available.
Click my name in this comment (not previous comments) to go to my blog post where I have posted the alternate instructions.