[General Questions and Answers] quicksite:
This is a question I always keep forgetting to ask til it's too late and I've already installed a new rom, then re-installed all my favorite cab files.

This may be a "Beginners 101" question that I just never knew the simple answer to.

I have always presumed, perhaps wrongly, that apps that get installed to your storage card always install some .dll or registry files to the device, and thus when you Flash to a new Rom, all those dynamic links residing on your device which refer to your Storage Card app installations get WIPED OUT on the device... thus rendering your Applications on Storage Card no longer operational.

But maybe there is a "list" of apps which you've previously installed to your Storage Card which will work immediately again with your newly installed ROM on your device?

Because today I was moving from a previous ROM which had TouchFlo 2D installed -- to a new one that has TouchFlo 2D installed. After looking at the new ROM, I wanted to customized some of the touchflo elements, so I wanted to use the M2DC customization tool -- as I am not a code tinkerer and don't know how to find & replace specific components.

I looked at the Programs listed on my device that had just been flashed with new ROM, and I didn't see the M2DC app on it... So, just like I had to re-install, from my storage card, cabs for PCMkeyboard, WkTask, Google Maps, etc, I was prepared to install my M2DC .cab from my storage card. So I tried to. But after I would select where I want to place this program, on device or storage card, and I chose "Device", I got error message saying "Installation Unsuccessful. You do not have permissions to do (this)"... So I tried again this time choosing the Storage card, and I got the same error message.

So my conclusion was that for whatever reason, this particular ROM (this one, if it helps in troubleshooting this) was rejecting my installation of that app onto either the card or device. I figured, this just be a bug.

Later I was looking at my storage card thru file explorer, and I saw under Storage Card > Programs

a folder called M2DC ... and I figured, hmph, maybe it partially installed but got stuck due to this permissions thing. But inside the folder was the .exe app file -- there from all my installations done to the prior ROM. So I clicked it, and it launched the application ... though once it opened it did not accuarately display the current theme installed. Rather it listed themes I had installed for the prior ROM.

This is as far as I have gotten, because I don't want to go futzing with things that relate to registry or dll entries.

So, back to top: Am I mistaken? Do some applications that are installed to your storage card simply work regardless of how many new rom flashes you do? If so, what are these apps, or I guess, what are the generalized rules re how Windows treats those apps that had been prior installed onto your Storage Card?

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RELATED QUESTION: What is "Best Practices" re Program Applications on your storage card?

On my storage card I keep all my .cab files and other installers, plus my MP3s, videos, docs, my PIM Backup data ... But I have never ever given thoguht to this before now: On my Storage Card, in the Programs Folder, what do you pros do between ROM installations? Do you delete all those installed files from your storage cards, under assumption they should really be re-installed again after the device is flashed?

Or do you keep certain ones?

Awaiting the Big Mystery Revealed soon.. thank you