Hello, ononim, you wrote: O>>> Noooo, it is possible to pass in 64 the bit environment, to make that it is necessary, and to return back. O>>> But the compiler to such tricks certainly not to teach. Only , only a hardcore. >> at the time of MS-DOS something similar was possible, but there the environment scanty, as a matter of fact missed. In any Windows 10 expenses for switchings kill all scoring from 64-categories in the middle of 32 bit environments. O> do not kill, such switchings happen at everyone so if to do switching before what that long calculations that all will be since switching in other mode it is simple far jump with some , and an overhead charge at it corresponding. With the compiler to potter too it is not necessary, enough fair 64 , but depending only from ntdll.dll, then by means of this trick (for modern some correction is required) it in wow64 process, to receive the address of the necessary export and to pull them. At us multinuclear processors. They can be generalized with each other and is in different modes simultaneously (one in long mode, another in compatibility and the third in real) or not?