The problem:
I wanted to install Intel SSD Toolbox 3.4.0.400. After clicking Next a few times in the wizard and the actual installation has started, Windows reboots and the installation is interrupted. Nothing of Intel SSD Toolbox is installedor changed.
Additionally, for each interrupted installation, a number of folders called "IIxxxx.tmp" (xxxx = random characters and numbers) are left in the C:\Windows\Temp folder, each containing 300+ MiB.
The cause:
The first thing the installer does, is to run the included vc_redist.x86.exe. This is the Visual C++ Redistributable runtime installer - essentially an installation program which installs a few DLLs that the toolbox apparently requires. On my computer, the VC++ runtime installer determined my computer needed to reboot. The Intel installer should have ran this installer with the command line that instructs the installer to suppress such reboots, but it does not.
The fix:
Download the installer.Run it.
Wait while "Please wait while setup initializes".
When the installer is waiting for you to hit Next at the first step, do NOT press it.
Instead, open C:\Windows\Temp.
Find the LAST folder (order by Modified date) called "IIxxxx.tmp". Check the modified time - it should be just a minute ago.
Open the Dependencies subfolder. It should contain a file called vc_redist.x86.exe file, and a few DLL files.
Rename the vc_redist.x86.exe file something else or delete it.
Find any other exe file - I picked C:\Windows\notepad.exe.
Copy it to the Dependencies folder and rename it to vc_redist.x86.exe.
Go back to the installation wizard and hit Next to let installation proceed.
Hopefully installation should be fine.
After completion, the installer will ask you properly to reboot. Do so.
After reboot, make sure to remove all of the "IIxxxx..tmp" folder in your Temp directory to avoid wasting disk space.
Complain to Intel that the installer has a bug.
Note: If the toolbox doesn't work properly, or if installation now fails at a later stage, you might have a problem with the VC++ runtimes. One thing to try then, is to follow the instructions above, but copy the vc_redist.x86.exe file to a separate folder and run it on its own by just double clicking it. It should show you a GUI offering to install, repair or uninstall the runtimes. You could also try downloading the runtimes from Microsoft.
Please leave me a comment if this helped you or not!