I have Media Centre installed on my Packard Bell PC. Two weeks ago, the power supply gave in so I went to a hardware store and when I got paid last week, I got a new one which was installed for me. He also put something inside which I believe is a RAM (helps the computer run faster).

Anyways, I was soo happy to get my computer back on but now I have these problems:

1. I cant hear sound in live TV, only recorded TV. (When I got the power supply changed, I had to buy new speakers. The speakers that came with the PC had a purple and green cable but the new power supply only had a connection for the green cable so the hardware people said I should buy new speakers which I did, Phillips surround sound. One cable goes into the back and the other cable which is a socket, is the power cable).
2. I have to be at my computer when it records, otherwise, when I come back to view what I recorded, it recordes in Digital Audio (blue screen) and it records as it its been fast forwarded.
3. I dont have all the channels available. I used to have 78 channels but now I only have 68 (this doesnt include standard channels like Channel 4, ITV 1 etc). Ive downloaded the guide, I even went on the Microsoft technical website but the info doesnt coincide with what I have on my system... Its all gobbledygook

I know alot about computers but when it comes to the technical stuff, Im really basic so I will need STEP BY STEP instructions on how to resolve this.. If you need part numbers, tell me how to find them. I dont have the box for the power supply but I can always find out!!!

PLEASE HELP!!!!