Drive problem with Windows 8

I have a function generator PCSGU250.
When installing the drive my computer says that information about digital
signatures are missing.
I have a new ASUS computer with Windows 8.
How can I do?

Please uninstall the current driver and try this beta Win8 driver:

My computer says it doesnt have a program to open the file with.
Or I need to make a association in the programfile (and I do not know how or with what).

At you can download an unzip program.

The files are not zipped.

I really need help.
I have unzipped the files.
But I cannot run it.
When I try it says that is not connected to any program to run/open it.
With best regards,

Here you can download the detailed step-by-step instructions to install the driver:
(The instructions are for Windows 7 but applicable for Windows 8 too - I think.)