Allright so my issue may be a bit different after all: I had BITTorrent-Sync installed, but one day it had just disappeared. I downloaded a new install file (https://download-cdn.getsync.com/stable/windows/BitTorrent-Sync.exe) , but when I try to run it it just fizzles out after a few seconds (two entries ''BITTorrent-Sync.exe *32" show up in task manager for a few seconds, then disappear). All anti-virus disabled. No other clue to what is happening can be found. Win 7 Home Premium SP1, 64 bit, AMD Athlon 7450 Dual-Core, 4gb ram, launching install as admin. I have not experienced this with any other software. Thanks for your assistance.