Hi, I'm Jamie.
Sorry to hear that you're having trouble with this but I'll do my best to help.
Are you using the online version of Picasa?
Yes, sorry one second. Had a phone call.
Do you use the same email login for both currently?
Your pictures should show up automatically in google photos, granted you are using the same account
Are the photos that aren't showing up in google any of the following in picasa?
Going to open up to another expert to help you. Got to step out for a bit.
Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
If you open the picasa desktop program on your windows 7 computer. Can you see your photos there?
if not, where are they currently located at?
Also, would you like me to connect to your computer from here and work on the issue directly on screen? If so we can set this up via a secure remote assistance session. That session is guaranteed meaning if I cant help you then you will be entitled to a full refund of all fees.Otherwise, I can try and assist you via written support alone. Let me know how you'd like to begin.
This could be due to what folder those photos were in. Or, if some of them were stored on picasa online, and other were actually stored locally on your computer.
Can you tell by looking at the picasa program and comparing it to google photos if its a specific folder that didnt upload the older folders, or specific folders?
Also, have you checked google drive to see if it has a photos folder? https://drive.google.com/
Some of your photos may have went there.. So its worth checking as well.
You should be able to just create an online google album through picasa and then just move the pictures into there