Dear sir i am using sansa express 1gb .its not working at all.when i switch on the player it shows "sansa" for 2 min ,then it disappears.after that i wnt be able to open it.but my computer is dtecting when connected to it.when connected in'my computer'it shows removable disk (h)and (i)when try to open removable disk h by right clicking it says device is not formatted.and by cliking yes to format ,the system is saying that there's n device found.even i tried to format through disk management.in that the removable disk (h)is showing as unreadable

update it firm ware (download the firm ware from sandisk
site

Hope this helps. See the section about the hot fix first----- If you are using Windows XP: you need the following. Windows XP SP2 or higher Windows Media Player 10 or higher Download and install the latest Windows Media Player if it's not installed. If you are using Windows Vista: If the player is seen in My Computer when using MTP mode, but not showing in Windows Media Player. Download the hotfix from-->>> http://support.microsoft.com/kb/939211. Run the hotfix. Refresh the players driver Connect the Sansa player to the PC The screen on your player should turn on, show 'Connected' and indicate the battery charging or full. If the player does not turn on try other USB ports or on another computer if one is readily available. Ensure you are connecting directly to the computer USB port and not to a USB hub. - If there is nothing showing on the screen and the player does show up in as a storage device in an explorer window, then the screen is just not working. If you receive the error "USB Device Not Recognized" on the computer, the player is most likely failed. Additional troubleshooting is unlikely to correct the problem. Check under Device Manager 1. Right-click My Computer, and select Manage. 2. Click Device Manager on the left pane. NOTE: Sansa MP3 Players can connect to your computer in MSC or MTP mode. Exceptions are Sansa Connect and Sansa Express which only use MTP mode. MTP mode is the recommended and default method for Sansa Players when used with Windows OS. The Sansa player will show up on Device Manager's right pane as: 1. USB Mass Storage device (if the player is set to MSC) 2. Portable Device (if the player is set to MTP mode) If there is a yellow exclamation point (!) or question mark (?) beside the device, try to refresh the drivers. Refresh the drivers 1. Right-click the entry with the error mark, select Uninstall. 2. On the top menu, click Action then select Scan for hardware changes. NOTE: If a device with yellow exclamation point (!) continually appears and disappears, then the player is most likely failed. Additional troubleshooting is unlikely to correct the problem. Connect using MSC mode Connecting in MSC mode will help determine if there is a problem with MTP mode or with the Auto Detect mode feature of the player. You can use Forced MSC mode or switch the player settings to MSC. Instructions to connect in Forced MSC mode are listed here: http://kb.sandisk.com/app/answers/detail/a_id/61 Instructions to switch player to MSC mode are listed here: http://kb.sandisk.com/app/answers/detail/a_id/207 If the player is detected in MSC mode but not when set to MTP mode, try to update or reinstall the Sansa firmware NOTE: Sansa Express and Sansa Connect do not have MSC mode. For Sansa Connect you can try reinstalling the firmware using the Connect Recovery Mode. Additional troubleshooting notes: If you have replaced the Sansa Player and you still have problems getting it to recognize in the computer, then you may need to try some additional troubleshooting. - Try connecting on another computer. - Try using a different USB cable - Try connecting to the back USB ports which may supply better power. - If only MTP mode is not working, try reinstalling Windows Media Player For Windows XP try also download and install the MTP Porting Kit ......

Hope this helps. See the section about the hot fix first----- If you are using Windows XP: you need the following. Windows XP SP2 or higher Windows Media Player 10 or higher Download and install the latest Windows Media Player if it's not installed. If you are using Windows Vista: If the player is seen in My Computer when using MTP mode, but not showing in Windows Media Player. Download the hotfix from-->>> http://support.microsoft.com/kb/939211. Run the hotfix. Refresh the players driver Connect the Sansa player to the PC The screen on your player should turn on, show 'Connected' and indicate the battery charging or full. If the player does not turn on try other USB ports or on another computer if one is readily available. Ensure you are connecting directly to the computer USB port and not to a USB hub. - If there is nothing showing on the screen and the player does show up in as a storage device in an explorer window, then the screen is just not working. If you receive the error "USB Device Not Recognized" on the computer, the player is most likely failed. Additional troubleshooting is unlikely to correct the problem. Check under Device Manager 1. Right-click My Computer, and select Manage. 2. Click Device Manager on the left pane. NOTE: Sansa MP3 Players can connect to your computer in MSC or MTP mode. Exceptions are Sansa Connect and Sansa Express which only use MTP mode. MTP mode is the recommended and default method for Sansa Players when used with Windows OS. The Sansa player will show up on Device Manager's right pane as: 1. USB Mass Storage device (if the player is set to MSC) 2. Portable Device (if the player is set to MTP mode) If there is a yellow exclamation point (!) or question mark (?) beside the device, try to refresh the drivers. Refresh the drivers 1. Right-click the entry with the error mark, select Uninstall. 2. On the top menu, click Action then select Scan for hardware changes. NOTE: If a device with yellow exclamation point (!) continually appears and disappears, then the player is most likely failed. Additional troubleshooting is unlikely to correct the problem. Connect using MSC mode Connecting in MSC mode will help determine if there is a problem with MTP mode or with the Auto Detect mode feature of the player. You can use Forced MSC mode or switch the player settings to MSC. Instructions to connect in Forced MSC mode are listed here: http://kb.sandisk.com/app/answers/detail/a_id/61 Instructions to switch player to MSC mode are listed here: http://kb.sandisk.com/app/answers/detail/a_id/207 If the player is detected in MSC mode but not when set to MTP mode, try to update or reinstall the Sansa firmware NOTE: Sansa Express and Sansa Connect do not have MSC mode. For Sansa Connect you can try reinstalling the firmware using the Connect Recovery Mode. Additional troubleshooting notes: If you have replaced the Sansa Player and you still have problems getting it to recognize in the computer, then you may need to try some additional troubleshooting. - Try connecting on another computer. - Try using a different USB cable - Try connecting to the back USB ports which may supply better power. - If only MTP mode is not working, try reinstalling Windows Media Player For Windows XP try also download and install the MTP Porting Kit ........

See the section about the hot fix first----- If you are using Windows XP: you need the following. Windows XP SP2 or higher Windows Media Player 10 or higher
Download and install the latest Windows Media Player if it's not installed.
If you are using Windows Vista: If the player is seen in My Computer when using MTP mode, but not showing in Windows Media Player. Download the hotfix from-->>> http://support.microsoft.com/kb/939211. Run the hotfix.
Refresh the players driver Connect the Sansa player to the PC The screen on your player should turn on, show 'Connected' and indicate the battery charging or full. If the player does not turn on try other USB ports or on another computer if one is readily available. Ensure you are connecting directly to the computer USB port and not to a USB hub. - If there is nothing showing on the screen and the player does show up in as a storage device in an explorer window, then the screen is just not working.
If you receive the error "USB Device Not Recognized" on the computer, the player is most likely failed. Additional troubleshooting is unlikely to correct the problem. Check under Device Manager 1. Right-click My Computer, and select Manage. 2. Click Device Manager on the left pane.
NOTE: Sansa MP3 Players can connect to your computer in MSC or MTP mode. Exceptions are Sansa Connect and Sansa Express which only use MTP mode. MTP mode is the recommended and default method for Sansa Players when used with Windows OS. The Sansa player will show up on Device Manager's right pane as: 1. USB Mass Storage device (if the player is set to MSC) 2. Portable Device (if the player is set to MTP mode)
If there is a yellow exclamation point (!) or question mark (?) beside the device, try to refresh the drivers. Refresh the drivers 1. Right-click the entry with the error mark, select Uninstall. 2. On the top menu, click Action then select Scan for hardware changes.
NOTE: If a device with yellow exclamation point (!) continually appears and disappears, then the player is most likely failed. Additional troubleshooting is unlikely to correct the problem.
Connect using MSC mode Connecting in MSC mode will help determine if there is a problem with MTP mode or with the Auto Detect mode feature of the player. You can use Forced MSC mode or switch the player settings to MSC.
Instructions to connect in Forced MSC mode are listed here: http://kb.sandisk.com/app/answers/detail/a_id/61
Instructions to switch player to MSC mode are listed here: http://kb.sandisk.com/app/answers/detail/a_id/207
If the player is detected in MSC mode but not when set to MTP mode, try to update or reinstall the Sansa firmware
NOTE: Sansa Express and Sansa Connect do not have MSC mode. For Sansa Connect you can try reinstalling the firmware using the Connect Recovery Mode.
Additional troubleshooting notes: If you have replaced the Sansa Player and you still have problems getting it to recognize in the computer, then you may need to try some additional troubleshooting. - Try connecting on another computer. - Try using a different USB cable - Try connecting to the back USB ports which may supply better power. - If only MTP mode is not working, try reinstalling Windows Media Player For Windows XP try also download and install the MTP Porting Kit

Normally your Sansa Express would show up as "Sansa Express", which would indicate that it is in MTP mode. The Sansa Express doesn't supply a menu option to switch to MSC mode, which would cause it to show up as a "removable disk". Apparently your Sansa Express has somehow switched to MSC mode. MSC mode is necessary for upgrading firmware, in which case it's called "recovery mode", and it's possible that some combination of key presses (usually involving holding down the power/hold button) put it into this mode.

If you double-click on "removable disk (K:)", do you see a Music folder? If so, is there anything in the Music folder?

sir i always stop 2 play it for 24 hours and then click the main button .it shows sandisk suddenly off.so it means that it charge is low

what do u mean like isit not poppin anythinq up once it turns on?

Well, the most memory from a micro sd card the Sansa mp3 player can take is 2gb, because anything more will freeze up the player because it was not designed to read that much memory. So if you have a 1gb or a 2gb memory card, then you can use them.

Menu -> Settings -> USB Mode

maybe you should try buying new headphones,if that doesnt work send it in for repair (they will usually just give you a brand new sansa!!!)