Question can i install window 10 qith these spec


Yes you can, no I wouldn't. Things that run decently on that pc were designed around WinXp maybe breaking into Vista and therefore Win7. All the drivers, games, programs, software will be best used on 16/32 bit OS. A 64bit OS is just going to create issues with incompatibility.

Win10 needs a minimum of 4Gb, 8Gb for more modern games as they run 3-5Gb ram by themselves. 4Gb is going to be very restrictive.

With that, if all you plan on doing is websurfing, email etc it'll work but with the speeds of the components it's going to be very slow, most likely slower than XP or 7
Yes you can, I did and know of several similar ones. Although XP would be more applicable, it's not secure, On the other hand W7 is not any "lighter" than W10 which is more secure without need of 3rd party security.
For best results I would ad another 4 to 8GB of ram DDR3 is not too expensive and it's easier to add than DDR4.