Hi,
Can you run through the troubleshooting guide here:
http://www.displaylink.org/forum/showthread.php?t=896
Regrading the install issues - were the devices coming up with a yellow exclamation mark against them in device manager?
If so please try the following steps:
Right click on device in device manager
Select Driver
Select Update Driver
Select Browse my computer for driver software
Select Browse
Enter C:\Program Files\DisplayLink Core Software\
Check Include subfolders
Select Next
Thanks,
James