First & foremost you need to check whether your motherboard support HDMI output or not. As you mentioned you have HDMI driver & graphic card too. There are some problems which can't be handle by ourselves. Therefore you need a computer support expert. I am sure there are several computer...
Yes you may use it by installing the theme of Windows 8 to your PC. It can modify all the appearance of your PC to Windows 8. Remember, don't install pirated theme otherwise you may need to install your Windows 7 again.
I think that particular sector of your hard disk was corrupt. Instead of performing troubleshooting operations yourself, you must contact to data recovery expert. He will get your data back & then you may format your hard drive without any concern or you may switch for new hard drive too.
If the data you are trying to backing up are important then in my point of view don't take chance & call the data recovery expert. Or you may ask here for reote assistance too. Good Luck :)
Same issue occurred with me. I have contact the site administrator & they ask me to request another password by clicking on forget password. May be this will help you
I think you should uninstall your sound driver by using motherboard CD, & then re-install it. Make sure the process will go on smoothly without any interruption. May be this will help you out.