Neem's correct on this. 2GB is the bare minimum needed to
LOAD W10, not necessarily run it decently. That's why all laptop makers today give you at least 4GB of RAM. That's what is needed if you wish to be able to watch streaming video such as Netflix, Amazon Prime, Hulu, YouTube, etc. Less than that the video becomes choppy, laggy, etc.
You probably already know this subconsciously, as your other laptop with 8GB of RAM most likely doesn't suffer these kinds of problems.
Checking the Crucial Memory site, it looks like the Acer laptop will take the 2x4GB RAM you have. Here's that link for you to review:
RAM & SSD Upgrades | Acer Aspire 5741 | Crucial.com
The specs on the Crucial Site show the 5741 can...