Please help! No sound device installed on Windows 7!!! Sound and webcam doesn't

In any other sections of device manager do you have a yellow warning indicating something is not working properly?

Unless you are missing a controller driver I can not think of a reason your sound card would not be detected other than actual physical damage, which is a possibility.

No I don't have any yellow warnings. Missing a controller driver? What can I do about it? Can I somehow take in and out the sound card? Would that help? Where is it placed?

What happens when you "Scan for hardware changes"

It is in Device MAnager -> Action -> "Scan for hardware changes"

Nothing happens when I scan for hardware changes :/

In a notebook (and in most desktops these days) the controllers and sound card are integrated onto the motherboard. The only reason I hoped it might be missing a controller driver is because that is the only non-hardware failure reason I could think of as to why it wouldn't see the sound card.

Do you have any restore points prior to when it failed? If you have an old restore point I would try that. If you have a W7 Install DVD or restore disk I would run the repair option. And if none of that helped, which I suspect it won't, then I would back up my data to an external HD with Windows Easy Transfer and then I would take one last try with a full install. I truly suspect your computer is physically damaged and none of this will fix it but I would try it before I absolutely gave up.

Sorry, that's the best that comes to mind. Maybe somebody else will come along with another idea.