The basic question here is that after installing OS Selector, it will not recognize either my Windows XP or my Windows Vista partitions on my hard disk. Doesn't even come up as an unknown OS, just fails to detect them at all. When I try to run the manual OS Detect tool and point it to each partition it just says there is no valid OS on that partition. In the past I've used PartitionMagic 8 and it's BootMagic tool to dual boot multiple XP partitions and XP and Win 98. Always worked flawlessly. I'm building a new computer and the primary OS is Vista (off the shelf, not OEM) but I want to dual-boot XP for some apps that aren't Vista compatible. I've read that PM8 can cause problems with Vista so I'm trialing some other things including DD10 with the OS Selector. Before trying DD10 I had tried another product called BootIt Next Generation. Worked pretty well but I wanted to compare to DD10. With BootIt I successfully got Vista and XP installed on different partitions on the same hard drive and was able to dual boot between them just fine. I've got the same PC with the same Vista and XP partitions and just trying to replace BootIt NG with DD10 and OS Selector. DD10 and OS Selector installed, and I get OSSelector to come up when booting, but it absolutely will not detect either OS at all. To be able to boot back in to Vista I had to boot from the Vista install CD and run the startup repair function on that. What the heck is OS Selector looking for to decide there's a valid OS on a partition? Thank you.