Removable Storage ??

[nomadees]

I do plug my flash disk and mobile hard disk frequently in my t43. but recently, i found that in windows explorer, the drive letter of "devices with removable storage" is accumulating, from D,E,F,G .... until Z and going back again to D. It happens all the time I plug/unplug the removable storage. How can I solve the problem? Thanks in advance.