Use the instructions here to download the PSE10 trial software and then enter your serial number when installing.
I have gone to the URL you gave above and it takes me to a trial version of PSE 11 which I have downloaded. It did not give me the option to download PSE 10 or to put in my S/N of my PSE 10.
So, what I thought to be a free download copy of what I have already previously purchased, will now cost me for PSE 11 within 30 days.
I can provide my PSE 10 S/N if you want me to: email@example.com
Doesn't seem quite right that I now am forced into PSE 11.
I'd suggest phoning the sales dept of Adobe with serial numbers for both programs in hand. Hopefully you had registered them with Adobe when you bought them. Explain your problem & they should be able to help you as they did with me. If you didn't register your products there is still hope if you speak to hem. I hadn't, but they had my name associated with my PSE 10.
Alternately, you can buy an external disc drive.
By the way, be sure to update and verify your catalog before doing the transfer. I wish I had done the research before doing the data migration & update from PC with 10 to Macbook with 11.
For Lightroom, just download the latest update. Each Lightroom update is a full installation of the application (that removes the previous version if you have it installed). No special tricks required here.
For Elements, I tested the links from the link I gave you and it worked fine, downloaded Elements 10. Did you follow ALL of the directions? You have to follow steps 0-6 just to get things set up. The link in the instructions leads to the latest trial version (currently 11), but once you have things set up, you have to use a separate set of links below the instructions. These links won't lead to a web page, as they are direct file downloads.