Here is my problem I have an external hard drive connected through usb on my desktop using xp home edition it had a drive letter of f assigned to it and was working fine but I tried to access today and the short cut says that it no longer exists went to disk management and found that it is still working but with no letter assigned. I've also tried right clicking to reassign the letter but the only drop down I get is help... can anyone help me to figure out what's going on

Hi am eric try reset the system, change to another port, Install anti virus on it the system because most it may be virus.
If the problem persist cheek device manger if the drive was configured if it not and is working there before try and get another system to and put it if it work fine that mines your system as been infected but does not try and get another usb cable.