An anonymous reader writes "Microsoft executives have been telling the tech industry that if hardware supports Windows Vista, it will support Windows 7, but it now looks like that may not entirely be the case. According to CRN: 'But after a series of tests on older and newer hardware, a number of noteworthy issues emerged: Microsoft's statement that if hardware works with Windows Vista it will work with Windows 7 appears to be, at best, misleading; hardware that is older, but not near the end of most business life cycles, could be impossible to upgrade; and the addition of an extra step in the upgrade process does add complexity and more time not needed in previous upgrade cycles.' And here is CRN's overview of the difficulties Microsoft faces in asking enterprise users to walk this upgrade path: 'Across the XP-Vista-Windows 7 landscape, Microsoft has fostered an ecosystem that now holds out the prospect of a mind-numbing number of incompatible drivers, unsupported devices, unsupported applications, unsupported data, patches, updates, upgrades, 'known issues' and unknown issues. Sound familiar? That's what people used to say about Linux.'"