I can't read my memory cards from memory card reader connected through USB port to a Windows PC.

I can see an empty card formatted with FAT, it's ok. But the working card from the N810 couldn't be read.

Is there any way to read these cards using memory card reader?

Do you mean the internal flash of the device? If so you can't (as far as I'm aware) read it from a PC like you would a normal memory card.

You should have no trouble. Win explorer should see it. Try another PC and/or another reader.

I have same kind a problem:
I can see the card (8GB micro SDHC Kingston) in windows explorer, but when I plug the card into N810 it does not read it. Previously I have used diffrnt. brand card. N810 did read it for couple of times. After 2-3 times of putting in/out the card started to not showing up. I thought the problem is in card and I bought Kingston one, but the kingston did not work too.

**********Can you help please, is there any way to put drivers or somehow recognize micro card.

DM3: Sounds like you have a possibly bad adapter. I'm guessing that since you're using MicroSD and the n810 uses minisd, thus the need for an adapter. I'd switch out the adapter and try a different one. I had some reading issues myself at one point due to a bad adapter. If you don't have a spare, you can get a few replacement adapters off Amazon or NewEgg for a few bucks.

Not the internal flash, but the external microSD card in the miniSD adapter.

The card reader uses regular SD format, so I use a big SD Adapter for the card, and Windows Explorer doesn't see it.

Well, yeah. The card reader can use an SD card. The other possibility is that the card reader can only handle SD cards and not SDHC like the card is. I'd try a 2gb or smaller card in the reader and see if it can read it, then try a regular SD card of 4gb or greater and see if it reads. That'll tell you if the reader supports SDHC. If it can't read the larger SDHC card, then you need to get a new reader.

Thanks, I'll try another

DM3 you can thank Lord Raiden by clicking the 'thanks' button on the right of his post.

BTW, the reader usually says SDHC if it is.

Actually, that's not entirely true. I've got a few SDHC readers that don't say anything on them except the brand name. They're more the exception than the rule, but there are a few cheap ones out there like that.