A laptop, Windows 7 Home Premium 64-bit. I adjust the volume with the taskbar slider, and even using the mixer to turn system volume to 100, it's never loud enough. Certain games are barely audible without headphones. It's never done this before.
Go to Control Panel and select Sound. In the Sound box under playback check that speakers are set as the default device. Double left click on Speakers and then click on the Levels tab and check the position of the volume control, there may be room to increase it, just click on the volume control and drag it to a higher setting. Click on OK then OK again. Play something and see if it is any better.
Open Device Manager, look for your audio device under Sound category, rt click Select Properties then the Driver tab
> Does it say provider is Microsoft? If yes, you're running with Microsoft generic drivers. You need to download the hardware specific drivers for your audio
The correct drivers for your sound card should be available from the PC's manufacturers web site.
When you say "after my most recent format" I assume you did a clean install of the OS, did you re-install all the mobo drivers? Was your PC supplied with a drivers disc?
Post your PC's name, manufacturer and model number.