Were the older drivers in Programs and Features. If not were they in Device manager. Look for anything with a yellow flag in Device manager and repost back.
Go to Start > Run, ad type msinfo32, expand the components section, click sound device and provide me with that info as well.
If it sates a WDM Windows Driver model, you are using Windows build-in in driver.
check the Windows 7 Compatibility Center here:
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