Where can I find my key of the previous version?

I bought Parallels Desktop 9 for Mac at the first time around 3years ago then I upgraded it to Parallels Desktop 11 for Mac Upgrade in November 2015.

I reset my Macbook today and wanted to install Paralles Desktop 11 but I couldn't do that. I've just installed only trial version on my Macbook.

Then I tried to put my license key for PD11 to complete the installment several times but your dialog box showed 'it's just an upgrade key and must put the previous key in it.'

I don't have any idea to solve it because no matter how I'm taking a look around on my previous emails and documents from your company to find my PD9 key I can't.

Please help me out.

Thanks in advance.

Kyle

 

Thank you Swati,
I bought PD9 for Mac then almost 2 years later bought PD11 Upgrade for Mac from a reseller.
I've cleaned everything in my Mac book and reinstall everything from OSX yesterday as I told.
After all I figured out the key I know was such an upgrade key that couldn't use for authentication.
I found out I need a key I got already when I purchased PD9.
I'm attaching an image from my emails and my account page on your website.
Please help me once again.

Kyle

 

Please check your private message and reply us!

 

Thank you very much!
I got it and everything was going well with the key.

 

Glad to hear that, @KangilL !