THanks for the reply. but unfortunately. the 64 bit windows 7 on my desktop doesn't even detect the modem. Whereas while I was using xp there was no problem. I tried on my laptop which is a 32 bit windows 7 OS and the modem works fine.
really out of ideas. the modem is a eazytech LOGI 1001 modem. with a qualcom chipset.
Note: As the device was working fine on 32 bit win 7 and does not work on 64 bit win 7, then its clear that it does not have drivers for win 7 64 bit...Check the manufacturers website, if you dont find any drivers then you might want to think of getting a modem which is compatible with win 7 64 bit..