Why am I getting sound through 2 speakers only?

It depends:

-if you are playing a standards audio cd, it is normal that you get sound through 2 speakers as this cds are recorded in stereo mode, which uses only 2 audio channels.

-the above answer applies also to radio stations, they work in mono or stereo, so it is normal you get sound through 2 speakers.

-if you are playing a DVD, you should check on it's box how many speakers it support (in which audio mode it was recorded (stereo, surround, Dolby digital, etc). If it was recorded on stereo, the answers above apply. If it is an old movie, it is probably not recorded in surround nor Dolby digital. If it is recorded in surround/Dolby digital, you should check first of all that the cables that connect the speakers to the DVD player are properly and tightly connected. Also you should check the audio settings on the home theater setup menu.

You should also check the distance option on the speaker setup menu, and make sure the values there are the right ones.

-if you are watching tv, the audio signal from your /cable box/satellite has to go through the home theater, so the connections should be as follows: yellow rca from cablebox/satellite output to tv input. Red and white rca from cablebox/satellite output to home theater input. Unfortunately if you have a regular antenna or a coaxial cable, you will not be able to get the sound of your TV signal through the home theater speakers.

I changed the norm from ntsc to pal and when I try to access the menu so as to change it back, I am not able to do so. How can I solve this?

You will need to have a pal compatible TV so as to be able to see the menu, and though to change that setting back to ntsc. If you do not have a pal compatible TV, you should refer to the place of purchase so that the technicians there can change that setting back to ntsc.

I connected the system to my television and the speakers are not working when watching the television.