I have htc desire s and it can not access sd card which worked in it for a long time I have an HTC Desire S, and it cannot access SD card – which worked in it for a long time. The card works perfectly fine in another phone.

If I restart the device it works for several minutes. But then I receive an error message: SD card unexpectedly removed.

Any idea what I could do to solve this issue?
It might be due to a problem with the seating of the SD card in the slot. If you're sure it's firmly seated in the slot and the problem still exists, then your slot may be broken, per se.

Send it in for repair.