Clayto, Britechguy -- I also use a registry cleaner from time to time; however, this thread is about a problem with an OS not working with 7zip. Sometimes the problem's cause can be traced to something "disrupting, fixing, or tweaking" Windows 7, 8 or even 10.
A software example: I've used Avast AV for several years. Suddenly modern-day Avast often self-implodes [within my desktop and on the two laptops] with a missing dll error. Now, I can continue doing modern-day Avast the same way I've been doing Avast for years -- all the while hoping I get different results; OR, I can troubleshoot and resolve the problem by either changing operations what has worked for me for years, or by not using anymore what has worked for me for years -- and therefore get different, desired, results.
Thread-starter, in this game of software Chess -- your move now.
Edited by RolandJS, 21 February 2016 - 08:22 PM.
"Take care of thy backups and thy restores shall take care of thee." -- Ben Franklin revisited.
Backup, backup, backup! -- Lady Fitzgerald (w7forums)
Clone or Image often! Backup... -- RockE (WSL)
"I heard Spock finally got colander!" "I believe the word is Kolinahr." "Oh."