How do I make my philips TV HD?????

I have a huge philips magnavox TV. I'm not sure how big it is, but it sure is big. We have surround sound for it and a bunch of couches facing it probably 8 feet away. It's just a great expeirience watching sports and stuff on this TV. but the only problem: it's not HD. so it's like watching a huge fuzzy screen. And we have a menu on our TV so u can change the color, brightness, tint, all of that stuff. But, u know, I put to much color and it's blurry and stuff. Tell me what percent I should put each one at; like 50% or 100%:

here they are:

color:60%

brightness:100%

sharpness:65%

please list each one like that. Thanks for your help: PLEASE BE RITE XD

brightness:

sharpness:

tint:

picture:

and for the last one it says clearview, and there are 2 choices:

normal and enhanced.

In your answer please tell me like this:How do I make my philips TV HD?????
A regular tv cant just BE HD.How do I make my philips TV HD?????
Buy an HDMI cable!