PE10's odd behaviour in not asking for discs 2 and 3.

My computer complies with system requirements and I have a brand new 'unopened' PE10. The box has three discs. I installed disc1 and the serial number and I was not told to install the other two discs. The installation surprisingly closed down. There is a PE10 shortcut on the desktop and PE10 is in the Program Files. I can open PE10 with the desktop shortcut and everything seems to be there.

I felt uneasy so I uninstalled disc1 and reinstalled it, with the same results. I have used PE4 for many years so I am accustomed to Adobe Photoshop Elements. I have dozens of files in MY PICTURES that I would like to put into PE10 but I haven't done it in case something is not right.

Can someone explain why I was not told to install dics 2 and 3?  Are they needed? 

cogleylane