no sounds and can not access windows installer and can not get out of safe mode

I recently had trouble when i as playing bingo online the game kept crashing and i had to keep pressing F5 to get back to the game. I was advised to try Firefox instead of Google which i was using. It still did not help doing that I then accidently pressed Skype which was not used anymore and I tried to uninstall it but it would not be uninstalled after that my computer went into safe mode and i lost all sounds. My name is Sheila and i am a pensioner 68 and i use my computer a lot.I have tried resoring it back to earlier times but it still stays in safe mode i keep getting an error message saying windows installer can not be accessed in safe mode please how can i get it back to normal. I rung a lady technician at Sky last night and she has helped me to get my internet broadband go faster now. But she is going to ring me tonight to try and help me get out of safe mode. Another message i got when i used internet explorer said it would not work while Skype 3.25 was installed that is why i tried to uninstall Skype i put it on 4 years ago so i could talk to my sister who had moved to thailand but she stopped using it. So that is why i tried to get rid of it. please can anyone help me.