I'm not using either of them Explorers. Not the Windows Ex, not the Microsoft Internet one, not the vehicle of such name. While there are reasons for each, today it's the first one.
Among other file managers, I played with Geos (or was it Beos?) and a couple of other wrappers around the explorer object, and settled on Ghisler's Total Commander for the last nine years, and still haven't looked back. Two main differences: there's a generic file viewer, and there's the command line.
Under WE (and most of the wrappers), it's a major (admiral, if you ask me) PITA to look into a file. First, you have to rightclick it and wait for all the WE extensions to load; then see if there's an app
which can open associated with this type of file. Then find out there's none, select Open With, then wait half a forever for the list of available apps to be scoured from remote provinces of your disk.
In some cases, it doesn't even offer the Open With option, but instead forces you to read this:

Now this is funny. A so-called "operating system" doesn't know how to... open a file? Wow. And after... how many years now, nineteen?... it still doesn't know which program created which file. OK, maybe it doesn't even need to know - the user should know.
Or the user can use The Web Service. There can be only one.
Either way, there's no quick way: if I used the Web service (sorry, the the and the service aren't capitalized, but they think they can always capitalize on web), it would... go somewhere Microsoft, I guess. Never tried. Trying now, it goes
here. Amazingly, used my normal browser for it, not insisting on that other explorer. And no, it doesn't know jack about .pig files.
Or, selecting from a list will plow your disk for a while to find a list of registered apps (which are registered so they can be found quickly)(the irony of this wasn't registered and can't be found anywhere). Then you can pick one of the programs, if you know what you're doing. BTW, for .pig files, that would be one of the old DOS gaming platforms, was it the one for Duke Nukem, or 4GW or the one for ROTT or for Doom or Dark Forces - well, open and see... oops, you can't open because of the damn circulus vitiosus.
In case you pick a wrong program and you had the "always" checkbox checked, you're out of luck if you don't know the inner logic of the Redmondians. Because if you try to rightclick and fiddle with the properties of the file, you may find that if you want to change the
file association (we're all for the idea of associated files - every file should be an associate! No, an associeté!) (can I become a member of that association?) it may lead to a read-only dialogue, which is about as frustrating as the whole WE. I mean, the button says "CHANGE", for world's name, and when you click it you get to change nothing?!
All this fuss, and I only wanted to see what's in this file. It's actually a text file someone renamed. But the whole of Redmond couldn't figure it out - well,
Ghisler did. In Total Commander I just press F3 (imagine, a single keypress) or click the button on its bottom row ("F3 View"), and I get his lister.exe showing the file. It takes its best guess as to the format of the file, so if it's an image it may try to show it; if it's a mp3 or avi it may play it. For most of the rest, it will display it as text, no matter what it is. So you get some gibberish, but you aren't stupid, you know there are unprintable characters, and among them there may be printables too. You scroll and find some text which makes sense to you. Maybe it's the MZ in the beginning, the signature of DOS/Win executable, or a PK (a zip), or JFIF within the first 10 bytes (a JPG), or %PDF - guess what this is. And if lister guessed wrong, you can always tell it to look at it some other way - as text, as Unicode text, as a webpage, as a RTF, as hex, as text+hex, in OEM or ANSI codepage...
Which is why I still don't understand programmers who ask questions like "how does one open a .dat file"? AAaaaarrrrgh! Look into it, open it low-level, and extract what you can or just call it a night.
But which is not the pretext I had for writing this. The command line... which is where you can pass parameters to whatever you're running. In TC, it's fairly simple: your command line is a simple long textbox with MRU history, and you can type the name or command or just highlight it in the file list above and ctrl+enter to copy it (ctrl+shift+enter to copy full pathname) into the command line, where you can then type extra parameters and you're done.
At times I have to use machines where I can't have TC. The remaining non-whites in my beard may soon give up because of that. How do you run a command or executable with parameters? In Windowses, that is. In TOS on the Atari, it was simple - the executable was a .ttp file, where tp meant "takes parameters", and it would prompt you to enter them before actually running.
In DOS, it was sort of simple, but you had to know where you run it. Your exe may have found files it needed on the wrong place on the disk, depending on your path, or may not find them at all. The systems having grown too big for this kind of logic - you aren't running just a dozen of apps so that all their directories can be part of the global path (and even back then when this was done, it wasn't nice). So you need to know
where to run the app, or to have an app which can find its pieces (by having the locations registered in the, ahem, registry or in files in its home directory), or which doesn't need any pieces and can work anywhere.
With TC this is not a problem - at any time you know where you are. You can run the app from the left window on a file (and in the location of) the right window by stating its full path and running it with right window active - that's where you are.
Without TC? Only one solution I know of: DOS prompt. Which is your command line sans steroids. You have to navigate to where you want it to run (or, using TC, run CMD where you want it :), type the name of the executable, type the parameters and then wait for the app to run its course, because it will steal the focus from your DOS window and you may not be able to close it until the app exits.
I've heard the "start button, run, type the name of your app and any parameters". Works if your app is on the DOS path, or if you type (or paste) the full path to it, so the run command will find it and run it, and if your app doesn't mind being launched from your "document and settings" folder every time. Because there's no way to tell it where to start.
I have a dozen other reasons for not using WE at all (not even to display the desktop - my shell is
bbLean). This much for today.