Why am I unable to connect the ereader to my windows 10 laptop?

Had the same issue. Tried with many cables, just two of them worked for my ebook reader. The cable should be data USB cable. The charge-only USB cables can not transfer data. Here is a link that describes the difference between the two types of USB cables.

https://www.dignited.com/50330/usb-data-...

I had the same problem - spent hours googling around and trying anything i could think of. In the end I had no luck and just could not get books transferred onto the reader. Then by accident, I found one way around this. Try Calibre which now has a function whereby you can use it as a content server. Then from the reader turn on wifi and use the browser to navigate to your calibre server and download from there.

I’m / was having the same issue. Even in the Device Manager > Universal Serial Bus Controllers > none of the subnodes change when plugging in the PRS-T1 Sony E-reader.

Solved when trying the third USB kabel.. aparently manufacturers think it’s convenient to not standardize technical specs and details.

Had this problem for a long time until Microsoft recommended trying a USB hub (cheap). When I plugged the eReader into the hub, hub into the laptop, Windows was able to recognize it. Worked for a few years. Just tried it again this week and back to not working. Checked cables, hub (even bought another one), eReaders (have 2 in the house). So, we’re back to the problem being Windows/laptop. Possibly an update, though I backed out whatever I could since the last time it worked. SOOO frustrated since this is how I transfer library books. Would love any other suggestions.

It's USB cable!

Tried many, some didn't even charge, some did charge, and just one (the thickest I have) actually connected to Win10 machine.

I had this problem, and tried a lot of solutions. I eventually got it connected by trying a few different USB cables. Most of mine didn’t work, but then I found one that did.

It's possible that your laptop does not have the necessary drivers installed to recognize your ereader. You can try downloading and installing the latest drivers from the manufacturer's website.
Solution you can try: There may be a software issue with either your laptop or the ereader. Try restarting both devices and see if that resolves the issue.

For anyone still having problems connecting and/or moving books to the reader, there are several things to try and things to be aware of:

First, now that both Sony and Microsoft have discontinued support it is a bit harder. Hard to find drivers if you need them, (but you shouldn't) and pointless to get hold of Sony's reader software since you can't use it for much anyway. (except your Adobe Digital Editions if you use that, but without store access) You should be able to connect via USB (A or C) to micro USB (B) IF you use a cable that is both charging and Data, many cables are only for charging as others have discovered and remarked. Your options are, once you have the proper cable, to use a file manager like explorer, to read the device as external storage and drag and drop files as you would with any other external storage device. In Calibre, if you can't get it to recognize the device, that's OK too, just use the 'folder option' instead. And lastly, should you be unable to do any of those things, get a 32GB (for the t3 anyway. max size) micro SD if you don't already have one, and a card reader to copy them directly to the SD card with your computer.

Too, you might not be doing one essential little chore, You must 'enable data transfer mode on the reader before the computer can get access to it, tapping the bar at the top lets you choose to change from charging to Data! Hope that helps some or all of you.