lost all outlook 2013 files when upgraded to windows 10

Hello Martin,

Welcome to Microsoft Community.

I am sorry to hear that you seem to have lost all Outlook 2013 information after upgrading to Windows 10.

In order to resolve this issue we need some information. Let us know the following:

Outlook information is stored in a PST file format if you are using a POP3 (POP/SMTP) email account and in case you are using an IMAP, MAPI or Microsoft Exchange account the data is stored in an OST file which can easily be accessed again – by reconfiguring/setting up the email account again in Outlook 2013.

Check what was the type of email account you had setup in Outlook 2013 prior to upgrading to Windows 10?

In case you had setup a POP account then you may check for a folder called Window.old on the C: drive (or your default drive on the computer prior to upgrade). On the Window.old folder check navigate to the following location and check if you can find your old PST file:

C:\Users\[USER_NAME]\AppData\Local\Microsoft\Outlook

Check the above and let us know the result.

Thank you.

i have a pop a/c and I checked the windows old file and it is empty there is also a windows old 1 and this is empty as well, I updraded from 7 to 8 in jan and got outlook 2013 at the same time and it seems that data file is gone, I have over 10, 000 contatcts missing and 4 years worth of business emails all gone.

it seems strange at he top of the page the quick step links are still there but when you click them it says folder cannot be accessed it's like the file has been deleted

the name of the pst file is the same that i was using before but all the data is gone

also this may be separate seem strange but I also cannot send any emails since the upgrade either you can send test emails and I can receive them but it just says cannot contact to network, have created new pofile and have gone in to program feature to reapir office, have started in safe mode and nothing

Yep, I have had a similar experience

Just upgraded to Win 10 from Win 7, on a 32 bit PC

Originally I was working from Outlook 2010;  However a year or so ago I upgraded to Outlook 2013 (I note now that outlook 2010 still remains  on the computer)

but after win 10 upgrade, the button on my start bar for Outlook 2013 has disappeared completely- as has any reference at all to Outlook 2013 ever being on my computer

I HAVE found the pst file, and the date stamp looks current - but it will only open the file in Outlook 2010

I do notice that Win 10 has reset my date formats to the US standard - how the upgrade software missed preserving that simple user setting, I will never know.  

You cannot have two versions of Outlook installed, you need to uninstall office/outlook 2010 then probably repair office 2013

Programs & Features will show what versions of Office are installed

You reinstall 2013 by logging on to the MS Account you used in its purchase.