Installer may be more user-friendly

[Slavic]

Currently we have two options to install TC: using the Internet connection and using the previously downloaded setup files. However, by default the setup is programmed to use Internet connection first, and an option to use the local files is available only by command line parameter.

If we attempt to run the installer without Internet connection, it greets us with Error message with HTTP error 12007 in the title, and then shows the more descriptive information that setup cannot continue and will end. This behaviour occurs even if we have the files tcmain.inf and one or more *.cab archives (like totalcmd950b7x64.cab), which in theory would allow to install TC locally. But this option is not available by default and even isn't explained in the info text. The installer's behaviour should be more user-friendly and more intelligent.

My suggestions:
1) It should check the presence of tcmain.inf and allow us to get to the main start screen even without Internet connection. Also it should check the file(s) listed in the local tcmain.inf and if one or more exists, it should allow to install this TC version regardless of Internet connection.

2) Checking whether the machine is connected to Internet should be non-destructive. In other words, installer shouldn't show the error message and prevent any subsequent operation. It may show a warning like TC does: when we attempt to check for update without Internet connection, TC shows an information that ghisler.com host isn't found. Maybe our PC has a temporary connection problem which can be easily fixed in a few seconds, like a loss of local Wi-Fi network. So, we should have an option to connect again without restarting the installer.

3) If the installation files are ready and Internet connection is available, installer may check whether the local files are the most recent. If yes, and we want to install the TC from existing local *.cab, no reason to re-download it.

4) The installer should check the currently installed TC version, and if the upgrade is unnecessary, it should warn us. Then we may have some choices:
a) Stop the installation, because we already have the last version;
b) Fix the (maybe) broken TC by updating all required binaries with good ones;
c) Completely re-install TC by deleting all binaries and user configs and install TC anew.

[DrShark]

However, by default the setup is programmed to use Internet connection first, and an option to use the local files is available only by command line parameter.

I think this is done this way intentionally, because:

This is done just for the beta test. I want to avoid that people installed old buggy beta versions because my installer is available forever on some internet sites. The new beta installer always offers the latest beta to install, and still allows to go back to older betas.

(underline added by me)