How do I convert Outlook from Office 2016 back to office 2007

Did you try to attach it yet?
I personally never experienced an issue going backwards, but then again I never tried a gap this great between versions.

Yes I have and 2007 cannot open it

This is an Elderly Person Issue

Not a Technology issue

Cjoego

what error do you get?

I have seen if you do not close out a PST prior to closing Outlook the PST has some lock on it.

Have you tried SCANPST.exe to see if it repairs it?
https://support.microsoft.com/en-us/help/272227/how-to-repair-your-outlook-personal-folder-file-pst

I have a client that had Office 2007 and upgraded to Office 2016

then Uninstalled office 2007 but hates the outlook

You need to have the DVD and installer file for Office 2007.

Uninstall all MS Office 2016 and install Office 2007 and do a custom install of Office 2016 to exclude MS Outlook 2016.

Have you tried doing a system restore to the point prior to the upgrade?

Tried the restore but  We migrated her over back in July no restore points

I have already installed 2007 but Outlook 2007 Cannot open a 2016 PST File

I installed 2007 on Test box and copied the 2016 PST file there Cannot open it.

Is there a Migration Path where I can migrate it out of 2016 into something else

then Migrate it back into 2007???

The computer is a Windows 7 64-bit Pro...and has no outlook Express

cjoego

@Shaun.  
I thought PST's are PST's and they were indifferent to the version.

Sorry yo-bee,  

It they were I would not be asking for a migration path

I will attempt to do Shaun's Solution right now.

Cjoego

Joseph have you tried the SCANPST.exe option yet

The pst is not backwards compatible, but you can open the 2016 in that version, and export the essentials, then open a new profile in 2007 and import it all.