I've installed it many times. Does not change the texture files..... I check the dates. I have firewall and antivirus disabled. I can rename the FSX texture folder and make a new empty one and it installs the files there with no problem. Rex4 will not overwrite files. Also it will not backup files. I have it installed in the root e: drive not in a program files directory. Same drive as FSX steam, but not inside it. I have REX essential and it works fine. I have given total permissions and sharing to all in the REX e: drive. I'm in win10, 64 bit and 32 gigs of ram. Any ideas?