You can install the first ISO first. When you are prompted for another DISK, load the second ISO file into the virtual CD-ROM drive where the first ISO was loaded. OK is OK (AI3 under me is like that....)
Normally, 32-bit systems cannot read 64 bit files, but vice versa.If you want to install it, you must burn a disc, or use UltraISO to burn it to a USB flash drive to start it