Since updating to Yosemite and Parallels 10 I have the following problems - aa) Windows 8.1 boots OK; Going into '.psf' or 'Home' drive and Windows Explorer address bar starts filling slowly looking for files - This goes on for ever and nothing comes up. If you start clicking around, Windows becomes unresponsive and the whole windows screen turns white. During that time the Mac also slows down to a crawl. Only resolution is to shutdown Windows. Sometimes I can go one or two levels deep in the Shared drive before above happens. bb) Starting Windows 8.1 and the whole machine seems to hang (VM is even before the BIOS stage). A minute or so later, the VM starts booting and the whole machine becomes responsive again cc) Windows 8.1 boots and then the whole machine becomes unresponsive (and whole of VM screen turns white). I have tried the nvram boot-args = debug 0x... solution mentioned by others, no effect. I've installed the 10.1 update to Parallels, same. I have uninstalled everything and installed Parallels 9, VM hangs when pressing the start button. Reinstalled 10, nothing... This is simply ridiculous - VMWare Fusion seems to be working OK. Any ideas? Thanks