Modem Troble

I have an Actiontec 56k Fax/Data Modem. now, everytime i Install the correct driver from the manufacturers CDrom, It works fine once , then after that, it cant detect the modem after the next connection. Now it cant even query the modem on the Diagnostics Tab. I dont know what is the problem, only the lights MR and CS are swithed on, it works fine on Win ME with the MR, TR, and CS lights open, then when dialing, OH also switches on, but in Win 2000 Server I cant get TR or OH at all.