Below on this IBM page, you will find links for downloading 25R3040 x335 driver you need.
A Quatech DXI3500 driver is an important program for your IBM laptop or computer, as it promotes correct functioning of your 24N5GF7A1K2 device. Moreover, a driver can promote correct functioning of any other device, e.g., a printer, a scanner or a display card. As a rule, your Cyclades ATP0001001 unit is already furnished with a CD with the proper 25R3040 x335 driver set. If the CD is lost, please take advantage of the Cyclades ATP0001001 link for 25R3040 x335 downloading.