MPM 2.9.3478 cannot open the Update Wizard:
MiKTeX Problem Report
Message: The update helper could not be found.
Data:
Source: Programs\MiKTeX\PackageManager\MFC\MpmView.cpp
Line: 1193
MiKTeX: 2.9
OS: Microsoft Windows Vista Ultimate Edition, 32-bit Service Pack 2 (build 6002)
SystemAdmin: no
PowerUser: no
Root0: E:\Users\Ralf\AppData\Roaming\MiKTeX\2.9
Root1: E:\Users\Ralf\AppData\Local\MiKTeX\2.9
Root2: E:\TeX\local-svmult
Root3: E:\TeX\local-adds
Root4: E:\TeX\local-fonts
Root5: E:\TeX\local-komascript
Root6: E:\TeX\local-rh
Root7: E:\TeX\MiKTeX29
Root8: C:\ProgramData\MiKTeX\2.9
UserInstall: E:\TeX\MiKTeX29
UserConfig: E:\Users\Ralf\AppData\Roaming\MiKTeX\2.9
UserData: E:\Users\Ralf\AppData\Local\MiKTeX\2.9
CommonInstall: E:\TeX\MiKTeX29
CommonConfig: C:\ProgramData\MiKTeX\2.9
CommonData: C:\ProgramData\MiKTeX\2.9
Identical issue here as well with the newest version of mpm-mfc.exe. I noticed in the code at the referenced line that it only looks for copystart-admin regardless of invoker which is an issue for non-admin accounts (especially with the portable version).
Same issue here with a portable MiKTeX x64 install on Windows 8.1 x64. Please fix this :(