Hello, I did not see in a search where there was a topic specific to this (and I may have just not searched well). I have Windows 7 SP1, and a PCI XFi Sound Card (possibly the pro, but I don't think the versions matter as much). After installing PAX MASTER PCI XFI ALL OS Driver Suite V1.10, the sound crackles and pops and eventually freezes up. Using another sound option (a USB headset) the sound still works, but this is not processed by the sound card. Crackling sound occurs on system sounds, WinAmp, Media Player Classic, and website flash audio. I have uninstalled drivers and installed Driver Suite V1.20. The problem is still there. I was successfully using a previous version of PAX, but I cannot remember which it was.