This should solve your problem. It did for me and my UA25-EX.
 
Go Here:
 
http://catalog.update.microsoft.com/v7/site/home.aspx
 
You'll need to use IE 6 or later. (IE 11 is available in Win10. Just search Win 10 for Internet Explorer).
 
Once there search for "ROLAND". Your device is on the third page of eight.
 
There are two drivers. The one sized 609 KB is for x64. The other for 32 bit.
 
Add that to your basket.
 
Click View Basket.
 
Then Download.
 
Unzip that file.
 
Then go to Device Manager and find your device.
 
Click the Driver tab, Then Update Driver and select Browse My Computer for Driver.
 
Select the .INF file from your unzipped download file.
 
You should be in business.

As a comment on Pentagore's post. I have two DAWs. On my older DAW the driver for my UA 25-EX was installed when I updated to Win 10 from Win 7. On my newer DAW it did not. I'm not sure why that is but for my newer DAW I had to do a manual find and install.

Good info! Glad you posted that.

I joined this forum just to say thanks to Mr Mooks for his info on getting the UA-1G driver for Windows 10.
 
It did not "download automagically from the web" as promised by Roland.
 
My device is working great at 24/96 now!