It's no secret that modern security programs in the form of standard or portable antiviruses quite often behave completely unpredictably (if not completely inadequate), often deleting files and folders that the user needs. And even the widely advertised and praised by many users "Kaspersky Anti-Virus" is no exception. Why this happens and what methods can be used to recover any lost data, then we will try to figure it out.
Why does Kaspersky delete necessary files?
Dealing with the reasons for this behavior of antiviruses (and not only the described one), we can definitely note the fact that the main reason for deleting files and placing them in quarantine is a potential threat from the object (explicit or imaginary).

Roughly speaking, almost all well-known antiviruses remove mainly executable files of programs that either interfere with the operation of the operating system or with the operation of the antivirus. If everything is more or less clear with the latter (the self-defense of the antivirus works), then why does this apply specifically to applications that the user, say, downloads for installation on a computer from the Internet?
The main problem here is that some objects are already initially entered into the anti-virus databases, and anti-viruses only need to know their name in order to block or delete them even without any structure check. Apparently, many have noticed that very often this applies to all kinds of key generators that are used to create activation codes or licenses when hacking paid official software (for example, files like KeyGen.exe, which may be present in unofficial distributions). Despite such strict measures taken by security modules, it is quite easy to bypass their restrictions and restore deleted objects.

Note: so that the antivirus does not react to such "seeming" threats, while downloading files from the Internet, it is easiest to turn it off for a while, install the required application, activate it (if required), and then bring the antivirus back to the active state.
Set up exclusions
But back to the described antivirus. For now, we will assume that the removal has not yet taken place(antivirus was disabled during download). In principle, you can immediately add the necessary objects to the exclusion list, after which the files and folders contained in it will be ignored during scanning.

Call the main settings of the program by pressing the button with the gear in the lower left corner, and then through the advanced settings section, go to the threats and exclusions item. You can immediately uncheck the option to detect other programs, except for the threats listed above, and then click on the exclusion settings link.

Press the browse button to specify the path either to the file itself or to the folder containing it. The second option looks more interesting (though less secure). For example, you can specify to ignore the Downloads folder, after which everything that is placed in it will not be scanned by the antivirus.
Kaspersky deleted files: how to restore them directly in the antivirus?
Now consider the situation when you did not have time to set the above settings. We assume that Kaspersky deleted the files. How to recover lost information? It turns out that many users are completely unaware that such actions can be performed directly in the antivirus interface. Actually, deleted objects are simply placed in a special place on the hard drive for quarantine, but they are not physically erased from it and are stored in the created backup copy.

To restore, you will need to go to the storage section in the settings and on the tab of the same name, simply select the necessary objects, and then click the restore button.
Frequently used file recovery programs
Now suppose that for some reason the operation described above failed or the threat was so obvious that the active antivirus prevented it. Again, we assume that Kaspersky deleted the files. How to restore them if the protective module's own means do not give the desired result?
To do this, you can use special applications, just designed to perform such actions. On the Internet, you can often find many recommendations regarding the use of the Recuva utility. Keep in mind that in most cases it recovers only a very small percentage of deleted information. It is better to use programs containing Unerase or Undelete in the name. However, if you want to achieve the maximum effect, it is better to use the two most powerful utilities.
Recommended utilities
This, of course, is about free programs for recovering deleted files R. Saver and R-Studio. They are very similar to each other. However, the first application is more simple and is designed for use by users with basic knowledge, and the second program is able to reproduce even modified file systems, not to mention the fact that it restores such objects that users do not even know exist.

In any case, you just need to select a partition or media, activate the start of scanning, and then, when viewing the results, select the desired file and restore it, specifying the required location.
Note: when using the first application in a portable version, you cannot set the partition in which the program file (R. Saver.exe) is saved for scanning!
And one more caveat about some situations regarding the fact that "Kaspersky" deleted files. How to restore information in the second program, if you did not find the desired object in the main results?

To do this, you will need to use a special additional directory. It usually contains multimedia files, however, it is also impossible to exclude the possibility of the presence of the object you need there, so it’s better to spend time and analyze the results in all the folders presented. It is quite possible that in them you will even find those files that you considered irretrievably lost.