This is the procedure required for a Windows XP installation:
1) Download the driver from here and unzip to a folder.
2) Plug in the interface. The 'Found new hardware wizard' will start:
Select No and continue.
3) Select 'Install from a list or specific location (Advanced)' and continue.
4) Select 'Search for the best driver in these locations' and include the folder where you unzipped the driver files in the search.
5) XP may complain the driver is unsigned:
Press: 'Continue anyway'.
6) The driver will install:
7) After this the Serial port will be detected. Follow steps
1 - 6 again.
8) After the driver has successfully installed right click on 'my computer' and select the hardware tab.
Press 'Device Manager'.
9) Explode the ports section and note the USB serial port number (COM5 in the example).
10) Right click on the USB port and select properties. Go to the 'port settings' tab and press the 'Advanced...' button.
Ensure the latency timer is set to 1. You can select a
different COM port number if you wish.
11) Start ElanScan, go into the 'Setup' menu, select the 'Set COM port' menu item and set to the USB COM port.
12) You're ready to use ElanScan!
13) Some helpful information is given in the WikiLEC. Please feel free to add more information that may be useful to the Elan community.
14) If you haven't done so already, download a copy of Alan McNichol's (aka ESM or ElanScanMan) superb free diagnostic program for the Elan from here.
15) If you want to unleash some extra horses, visit Alan's chip shop for a professionally engineered upgrade which maintains all of Lotus' inbuilt safety features.