Update doesn't work for me.
I install the core update (gtos_cu_581c1_eng.exe) and that seems to work. I've selected the right file location and I've got the previous updates successfully installed.
When I run the update utility and select (gtos_patch_march13c4_eng.gt2extension), it causes MS Notepad to open a file called "last_bug.txt".
The text in the file reads: