No clue about your sound problems.
I have Windozer 7 64-bit and UHal works fine w/no modification - almost.
Technology for MSAgent was done away with but you can get free download to fix it from Microsoft.
You will have to use Search on MS web site, because I don't know the URL.
Hal might be old, but the newer versions are new. It's just that I don't know if Hal will run w/out the MS Agent technology - Haptar engine might not have anything to do with it.
Also, I've read, but have not tried it:
Log on as Admin. Completely disable any and all security incl. firewall. Unplug from internet.
When you install software (not Hal), and SetUp asks where to install, choose Program Files - Not Program Files (x86)
After install, Win 7 is supposed to know to run it XP-compatible.
Again, I've not tried it, and I'm not talking about Hal program, but it seems reasonable that XP programs may run from there - otherwise, why 32-bit Win 7 and two Program Files folders...