a general question, but since i'm asking because of FIrefox i created this topic in the Firefox Subforum.
Can i use an installed version next to a portable one? Especially at the same time? Without loss or corruption of any data?
I'm asking because of the folders FIrefox portable creates at start and deletes at closing...
Yes, it is possible to run an fully installed version of Firefox and Firefox Portable at the same time and neither will interfere with the data of the other.
For how to do this, in the Firefox Portable install folders, drill to the folder path Other\Source. In that Source folder you will find a "Readme.txt" file and a "FirefoxPortable.ini" file. Open the Readme file and there are instructions there on how to get Firefox Portable to run at the same time as a fully installed version of Firefox.
You might need to read the instructions a couple of times before a bulb lights up on how to do it. Once you do get it you will see how simple it all is. Just remember that at all times you must only launch Firefox Portable by launching the FirefoxPortable.exe file - never launch Firefox Portable in any other way (it's okay to create a shortcut to the FirefoxPortable.exe file if you like and launch it via using the shortcut).
If you are new to Portable Apps then would recommend you read all the links supplied at the Support section of the download page. Doing so will help you to understand portable apps and get to grips with using them.
Use Portable Apps on both Flash Drive and HDD/SSD.