Since yesterday's (22.6.2015) update my MiKTeX 2.9 on a USB stick no longer works. Trying to start it on a Windows 7 desktop returns the error
Windows API error 2: could not find file
The only thing I can think of is a clean install, which I would rather not do.
mpm --install=miktex-vc120-bineverything was ok (perhaps you need ampm --update-dbfirst). – Ulrike Fischer Jun 24 '15 at 13:36