Can't increase recording level

Running Audacity 2.0.3 (from exe. installer) on Windows 7. I can’t seem to increase the recording level to more than -12db. The only way to get any sound is to select “Internal Mic” from the Sound tab in Control Panel. “External Mic” and “Line USB Codec” produce a high-pitched squeal. Can I get by with the -12db? or there a fix for this? Thanks for any assistance.

What are you trying to record?
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