Than I tried to install 64bit version to the flash, and it erased the program from the hdd. Again, I installed 64bit version to the hdd, it erased flash drive 64bit version. And just to test it, I installed 32bit version to the flash, and even this deleted the 64bit version from the hdd!
In every case I clicked "Yes" to
-Construct 2 appears to be installed on this computer. Do you want Setup to uninstall the old version? - but I think that shouldn't affect version in a different folder.
-I forgot, it also erased Kyatric's pathfinder plugin