Truly-, Clean-, and Dirty- portable.. impact on host .. a severity rating and modification disclosure

There is no such thing AT ALL as a truely portable app as, at the very least, every single EXE you run will leave an entry in the MRU in the registry and a file in the Windows\Prefetch directory. Windows itself does this and there is no way around this within the app itself.

Nearly all portable apps that are portable modifications of 'big' apps (rather than just small utilities) modify the host in some way and then restore it on close. Firefox, Thunderbird, Sunbird, Miranda, Gaim, Audacity, PuTTY, Nvu, KompoZer, GIMP. Nearly EVERYTHING. There is no way around this other than modifying the source, which isn't going to happen (too much effort, not allowed on the Mozilla apps, maintaining it would be difficult).

"Dirty" is NOT a portable app. It may happen to run without installation, but it is NOT portable in any way shape or form by the definitions used here. Nearly every other 'portable' site uses a much looser definition and calls apps portable even though they leave behind registry keys, stuff in APPDATA, file associations, etc.

I'm currently profiling my app (which I wrote, and DO have the sourcecode for), and am finding all sorts of crazy stuff.
Things that shouldn't write to the registry, do.
ex:
To get the user's appdata path (in case they want to store stuff there), I call
SHGetSpecialFolderLocation(0,CSID_APPDATA, pidl);
And then something in Windows writes the path to HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\AppData
Following that, a bunch of crap appears under
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2
Why? No idea.

Just starting the app causes 8 writes to: HKLM\SOFTWARE\Microsoft\Cryptography\RNG\Seed

I create an instance of IE, for showing HTML. That causes 4 writes to various keys under HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders

I play a sound (PlaySound() api), and I get a dozen other pieces of crap written for "soundpreference" "channelconfig" and "speakergeometry". WTF?

I'm using the "no registry" option in Armadillo, and sure enough, it writes to the registry. Man, I hate this. And I don't know of any guides (U3 or PortableApps in general), of what's acceptable/inevitiable vs. what needs to be cleaned up.

Hi John

Long time PFF (now FFP) user here, glad to see the portable definition is still pretty tight - however I reckon the situation could be improved a little.

Why not rename all portableapps launchers to start.exe, or even a common filename like calc.exe? This way, at least the prefetch folder won't be advertising "Tor, Recuva and Portable Eraser used on this machine while you went to the bathroom last night".

Also, since so many apps (CCleaner et al) clean the MRU list, can the PA launcher app perform searches in the MRU registry area based on the apps in the PA launcher's menu list, and remove entries if they are found? Can an app remove itself from the MRU list?

Anyway, maybe this would be a small extra step towards better-covered tracks. Let me know what you think...

cde

I meant to suggest that firefox.exe etc. would also be renamed, since that would have no effect on the app's functionality and the launcher could just be told to look in folder [whatever] for start.exe rather than to launch [path/file.exe].

I know that some apps have multiple .exe files and these could not be renamed without breaking internal functionality, but for single-exe tools it shouldn't be an issue.

I had no idea renaming exes was such a problem, but fair enough.

Maybe if no firefox.exe is found in the target folder the launcher could say "not found: [app.exe], use [foundfile.exe]?" or something like that? That way users who worry about prefetch data could change the name themselves, and no licenses are affected (I think)...

I know, I know, multi-exe apps would still be problematic, but such a simple step to sort-of-hide from the dreaded prefetch folder seems possibly useful for users who want to cover as many tracks as they can.

cde