> MS's track record shows, any of their "improvements" are not backwards compatible with old OSes. What do you mean? All new versions of all commercial softwar

> MS's track record shows, any of their "improvements" are not backwards compatible with old OSes. What do you mean? All new versions of all commercial software have new improvements/features. If they just released all of them for free on the previous version, they might as well just shut down their company. > Not compatible with Windows XP, yet Chrome and Firefox is still. Well IE since version 7 uses mandatory integrity control which is a kernel feature of Vista and above. XP only has DACLs. I believe what they did initially was just disable the protected mode feature when IE ran on XP. Firefox is woefully behind other browsers in this particular aspect so it doesn't need to worry about it. Chrome does the same thing as IE on Vista+. They wrote their own sandbox because its a cross platform product which is why it works on XP. So certainly, Chrome would be your choice if you want a single browser that runs on XP as well as Vista. That would matter only to businesses or computer labs or places where there is a large deployment of software across multiple OS versions. For home users, it doesn't matter. People just use whatever version of windows came with the PC.