is there any limit of operating systems compatible to be used on intel i3, i5, i7 microprocessors ???
can we install and use all MS operating systems ????????????
Win95/98 is out of course, and you may have some 'no-support' issues with WinXP (pre-SP3) or Win2k, depending on which chipset you choose for which version and which socket (1366,1156,1155) of i3/i5/i7, which includes several supporting chipsets.
Your chosen MB manufacturer will normally list which Windows OS variants are supported at their respective websites....
You should certainly be 'ok' with Vista and Win7 with any of the afforementioned processors....
Windows XP and Windows 2000 are probably the oldest MS OSes you can use. However, you may run into problems finding drivers that supports a few devices on the motherboard. It's best to check if the motherboard manufacturer have drivers available for Windows XP (which is more current than Win 2k).