Need memory card help please

We just got new phones and they take the micro sd cards. I bought one for each of us (total 3). They came with the adaptor. The cards work fine in the phones but when I put them into the adaptor and try to retrieve the photos and videos I get nothing. I have 2 readers, one is on my printer and one on my computer. The one on my computer doesn't show it at all, my printer keeps saying error. I have tried all 3 cards and all 3 adaptors.
If anyone knows what I am doing wrong, please let me know.

What does the manual that came with the phone say about transferring data to your computer? Some phones require a special cable that connects from the phone to your computer, and software is usually provided that is run on your PC to retrieve the data from your phone.

I can transfer from my phone to the computer, but I should also be able to put the card into my computer and get the info off of it.
I dont have a problem transferring from my phone, the problem is my sons phone didn't come with the cable and software. I did put his card into my phone and retrieve it for him but I don't want to have to do that every time. I was hoping to get the info by putting the card into the reader but I will get him a cable if I have to.
Thanks.

caroleigh wrote in post #5545329
I can transfer from my phone to the computer, but I should also be able to put the card into my computer and get the info off of it.

That is not necessary true. In many cases the card used in your phone is not formated with the FAT filesystem, so your computer has no way of reading from the card without going through the phone/cable method.

ah , I didn't realize that.
Now, I formatted my card through my phone, but my sons I did not format. Shouldn't it see the non formatted card?

How big are the cards, and how old are the readers? Some older SD Card readers can't handle more than 1 GB.

Jon wrote in post #5547046
How big are the cards, and how old are the readers? Some older SD Card readers can't handle more than 1 GB.

The cards are 4GB.... the readers are built into my printer and one built into my computer. I would guess they are 3 and 4 years old.

I bought the cards off of amazon and it appears they are not real sandisk (not really sure how to tell because I don't own any other micro sd cards) but the adaptor just looks weird.

Jon wrote in post #5547046
How big are the cards, and how old are the readers? Some older SD Card readers can't handle more than 1 GB.

...oh... and my 2GB CF work fine in my computer and printer.

4 GB crosses the (2 GB) divide to the SDHC specification; you need a different reader for those, one that's SDHC compatible (it will be backward compatible with SD cards, too).

Jon wrote in post #5547075
4 GB crosses the (2 GB) divide to the SDHC specification; you need a different reader for those, one that's SDHC compatible (it will be backward compatible with SD cards, too).

Thank you Jon, very helpful! That's what I needed to know, if it's the card/adaptor or my readers! I'll pick up a reader.