Trying to add a 4gb card to my sansa e250r mp3 player, but it doesnt recognize that the card is in. any help?

Sansa Not Recognized: Try connecting it to another computer the back straight to the motherboard ths should be USB 2.0 and see if it will recognize it as sansa or Drive/removable drive. if it does then download the sansa update software and install it. Make sure you disconnect the sansa and connect it when asked. This will update your sansas firmware and add the Usb Mode. Try to connect it to your computer at home it should recognize.... link for update software (http://mp3support.sandisk.com/sansa/Installer/1082/SansaUpdaterInstall.exe) download to a flash drive much easier. Make sure USB mode is MSC
Recovery Mode may also allow your computer to recognize the sansa
lock your sansa hold in the rec key on the left at the same time push the menu/power button this will take you to recovery mode then connect to the computer Start the update software when finished disconnect

sd utility.exe u download from google it wil dolve u r problem.......

Your model doesn't natively support SD cards over 4GB, however I hear you can install something called "Rockbox," it's a free third party firmware that allows you to dual boot between "Rockbox" and the Sansa firmware. "Rockbox" adds the support you need for SD cards with a capacity of 4GB or more. I've never used this firmware, but it does sound promising.
Download it here
Sorry I couldn't be more help.

Is you E280 V1 or V2? The V1 will only recognize up to 2GB. You can find this by going to settings, info. If the firmware number starts with 1 it's a V1. V2's start with 3.

If you have a V2 place the card in a card reader to format. Format card to FAT32. If not recognized by a card reader the card may be defective.

If the player is a V1 the micro SDHC can still be used by loading RockBox firmware. But note when running RockBox the sync port will be disabled. To use port the player can still be started in the Sansa firmware but a SDHC card will not be accessible.

http://www.sansaworld.com/
http://www.sansaworldmp3.com/

The player can read the card, but it is not going to add more memory space to the player. The function of the card reader is to enable your player to play songs that you otherwise couldn't play because the hard drive is full.

-Tha Mp3 Doctor

The player can read the card, but it is not going to add more memory space to the player. The function of the card reader is to enable your player to play songs that you otherwise couldn't play because the hard drive is full.

-Tha Mp3 Doctor

If the PC does not recognize the player, try this: disconnect the player from the computer, turn it off, hold in the volume + button, and reconnect the player to the computer while holding the volume + button in. Keep holding the volume + button for an additional 5-50 seconds. Windows should eventually go into recovery mode and revive the player- it will pop up a window that says Found New Hardware Wizard.

Check the Sansa tutorials at http://www.sandisk.com/Retail/Default.aspx?CatID=1468
to make sure you have followed all the steps first.

In my experience, every mp3 player/photo frame/etc with a card reader has a MAXIMUM memory limit for the type of card that it can read. It is possible that the Sansa player can only read 2GB Micro SD cards or smaller - and thisi nformation may not have been available when they printed the manual. If you have followed all instructions, and it still will not read the card, try switching to a 2GB Micro SD card.

try to right click the icon of the separate drive and click on explore

If the 4gb micro SD is a high capacity SD (it will say micro SDHC on it) your player may not be able to read SDHC cards, my sansa can't because it's the 'older version' it will read 2gb and below micro SD cards though (it sucked when I found out because I had just bought a 6gb micro SDHC)