Anyway to switch back to classic file explorer instead of using Windows 8 version that defaults to OneDrive

Have you tried this?

For Home Edition and Pro.

To get rid of it entirely or just remove it from the side panel.

http://www.howtogeek.com/167058/how-to-disable-skydrive-integration-in-windows-8.1/

Anyway todo it without modifying the registry? I am instructing someone over the phone who's not tech savvy

Is this what you mean?

Swipe right edge to left.
Pick Search
Type: onedrive storage space
In File Storage section, set Save documents to OneDrive by default to Off

Also check the Sync Settings section, under  Other Settings.

Possibly change: Web Browser, Other Windows Settings,

Would that disable the grey windows 8 file picker and put back the one that appears in windows 7 and earlier versions ..

I am referring to the file select window that appears when for example you attaching a file in a browser window (gmail attachment), etc

Another way - all Windows, no software - to have a Programs Menu for any activity in Windows 8 Desktop is as follows:

Right Click on the Taskbar
Select Toolbar, New Toolbar
Add the following content in the space provided:
%ProgramData%\Microsoft\Windows\Start Menu\Programs
Save the toolbar. It should call itself Programs.

See my article on ways to improve Windows 8.

https://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Windows/A_16620-Ways-to-improve-Windows-8.html

You can lead a person over the phone with this.

@Mark,
> ...disable the grey windows 8 file picker and put back the one that appears in windows 7 and earlier versions

If you mean the Metro file explorer GUI, which bears no resemblance whatsoever to that in Windows 7... then I believe to avoid that and instead, use the old-style Windows Explorer dialogs, is to switch to the Desktop. From there, Chrome, or any browser, for that matter, should give what you want.

What do you mean by switch the desktop?

On your keyboard, press the Windows key (Flag icon) and D key simultaneously. This opens the desktop. Look familiar?

To boot to the Desktop instead of the Metro GUI... http://blog.laptopmag.com/boot-to-desktop-windows-8-1-preview

- Go to the Desktop.
- Right click on the taskbar and select Properties.
- Pick Navigation tab.
- Set: Go to the Desktop instead of Start menu when I sign in

I will try it however Chrome was being launched from the taskbar  (not the metro UI)

Thanks...

Use the Program Menu I gave you. Works a treat and on Windows 10 as well.

John, I don't see how adding another Toolbar will change the default file explorer to pre Windows 8 (non Metro UI style)

The toolbar is in the tasbar and is readily available. You can try very easily to see if it fits you. I use it all the time.

But I won't have access to the taskbar while I am choosing a file from the 'select file' prompt ..

My whole thing is when attaching a file through chrome (email attachment for example through Gmail) .. That I can pick pick the file using the classic method instead of through the Metro UI

That's it, thanks a million!!!

And thank you everyone else for the suggestions

I don't have Google Chrome running on my RT (not supported). However, IE running on the Desktop does show the old-style dialog (attached)...
Capture.PNG

I just posted. I see you got it to work...
Nice. Thanks, Mark.
Have a good weekend...

You too, thanks