Running portable application from USB flash drive

When I run a portable application from USB flash drive (as opposed to a conventional program installation)
say a browser:
Does browsing get significantly slower ? (reading/writing is slower from/into USB drive).
What junk is being left on my hard drive after I remove flash drive?
Any Registry entries to delete?
Temporarily files ?
dll files?

I’m obsessed with cleaning all unnecessary junk whenever possible.

USB 2.0 (which any remotely modern device should support) transfers data at 480 Mb/sec. Compare to a 7200 RPM hard drive which only has a read rate of around 70 Mb/sec. So, no slowdown there (unless you’re using an old USB device, old USB adaptor, or don’t have proper USB 2.0 drivers installed).

As far as the drive goes, a standard usb drive won’t leave any crap on your computer just from plugging it in. Sometimes companies will load crap on there that might install on your computer, but that’s not normal (or very common in my experience).

So really, you just have to worry about whatever program you are running off the drive leaving things on the hard disk. If you’re worried about programs leaving crap laying around, consider using sandboxie which I think should work with a flash drive but I’ve never tried for sure. It lets you install programs into a ‘sandbox’ and they can’t write anything anywhere else on your computer.

I use Firefox Portable every day, all day, and I can definitely say that it leaves something behind on the computer’s hard drive.

Say I’m browsing the Dope on computer A, and the last thread I read is a thread about using portable apps from a USB flash drive. Then I find myself on computer B, browsing the Dope, and the last thread I read there is about sibling rivalry. If I then go back to computer A, Firefox Portable will return me to the thread about using portable apps from a USB flash drive.

That’s the essence of my question… so should I worry or shouldn’t I ?

could this info be stored on your flash drive rather than computer A hard drive?

Justifiable question from the abridged version I gave. To avoid all this “computer A” business, let me say that on any given day I move back and forth between as many as 4 computers at work, and with 100% predictability, when I go to Firefox Portable, it will return me to whatever thread I was last viewing on that computer.

It works the same way with Gmail, LiveJournal, and Google Reader, too, FWIW: it’s definitely reading something about its last state from the hard drive of the PC.

Now, it’s entirely possible that there is some setting I have missed that will prevent this. If anyone knows what it is, I’d be happy to hear it.

Here is an article I wrote on portable apps that could be helpful to the OP:

I hope it helps.

The answer to the OP’s question depends on *exactly *which apps he/she is running and on *exactly *which OS(es).

Windows has standards on where apps should store setup and configuration data, including things like browsing history. An app that was not specifically designed for zero footprint portable use will *likely *save things to the Windows standard location on/in the machine’s permanent hard drive / registry.

Windows itself may save last-used data about the app, and that will be saved on/in the machine’s permanent hard drive / registry.

Certain apps are designed to be zero footprint. But that may or may not include code to clean out information Windows generates & maintains on its own. And depending on your user rights or the machine configuration it may be impossible to remove that.

If what you are seeking is to use some program X with 100% certainty the owner of the PC won’t ever being able to detect that, well, you are seeking the impossible.

If you’re just a neat freak & don’t want to clutter up your Mom’s IE browsing history, there are plenty of low-footprint apps, including browsers. Note that is low-footprint, not necessarily zero footprint.

And this

is a fool’s errand. Windows records hundreds of things *per second *about all user’s activities. Since you’ve never heard of this, you haven’t been worrrying about it. Now you know and now you’re stuck.