SOIS has been packaged as a portable application that doesn't require a traditional install. You can run it from a folder on the disk or from any external media such as USB drives.
When you run SOIS for the first time, it installs the VDDK file system driver version "188.8.131.52216" on your computer if you do not have VDDK previously installed. If you already have VDDK "184.108.40.206216" installed then SOIS uses that driver. However if VDDK is some other version then you need to first uninstall VDDK before running SOIS.
Each time SOIS is run it extracts its program files into the logged-in user's temporary folder and then executes from that location. SOIS cleans up after itself when it exits and deletes all its files except log files that were created while scanning. SOIS however leaves the VDDK 1.2 driver installed on your computer so that it need not be installed each time SOIS is run.
SOIS requires the Microsoft Visual C++ 2005 SP1 Redistributable Package (x86) to be present on your computer before it can run. If this is not present then SOIS installs it the first time it is run. If you get errors during the installation of this package then check your Event Log for errors.
The installation process creates a log file named "sois_launcher.log". This file is located in the Windows temporary folder of the logged-in user.
Removing the VDDK driver installed by SOIS
When SOIS is run for the first time it installs the VDDK driver on your computer. To remove this driver you need to run SOIS on the command line and specify the --removeDriver option. You should reboot your computer after removing the driver otherwise you may face problems running SOIS the next time.