Windows 7 Realtek/ Audio issue

Hi there, I've been all over the internet to find a solution to this problem but to no avail- I hope that actually asking someone will help!I have a Toshiba Satellite L30-115 (which is discontinued since it it almost older than my granny) and recently upgraded to Windows 7. After the install my sound is gone. The speaker icon bottom right of the screen has a red cross underneath it and no volume options. When I go to Device Manager it says under general that the device is working properly and under driver that it's from Microsoft. When I go to Hardware and Sounds it says that there are no devices installed. I have figured out that I need a Realtek Audio driver and have downloaded numerous versions as I'm not sure which one is the right one. I also had Windows Update drivers and it updated and installed a Realtek update but it didn't help (I can't even find it on my system). I have no idea what to do next.Please help or I'll have to throw this laptop out of the window!Thanks in advance!