Cd problem?

hi i recently upgraded to a 64 bit m/board reinslalled windows etc and everything looked ok but when i 1st swich on comp and insert a cd or dvd in my nec 4570a it is recognized and will run however if i then eject cd/ dvd an then try to run a different disc the comp thinks the 1st disc is still there and wont run the 2nd disc if i reset comp the process starts full circle i.e comp now recognises cd/ dvd bnut wont recognise any subsequent discs until i reset making it a slow process lol any help would be much appreciated

the help offered was fantastic, being a tad facetious there, anyhow in case someone lse has the problem done a windows update problem solved