I have a portable installation of 4.1.23 running on a work machine. Seems to work fine but noticed it was freezing when left running in the background and not syncing. Have to close it from Task Manager.
Tried to update to 4.1.25. Only possibly portable version I see is the zip marked debug. When I try to run this my antivirus (Symantec) immediately pops up and quarantines the EXE. Risk shows as WS.Reputation.1.