November 20, 2016: Please see edit at the end BEFORE doing any of this!!
I have been having the same issue with my Silhouette since I did my Windows 10 update. I was able to get it to work again with the following steps:
Follow Sharief K's first two instructions (you'll have to have your Silhouette plugged in and turned on for this):
a. Press
Windows Key + R, type devmgmt.msc and press enter.
b. Expand
Universal Serial Bus controllers. Right click on the USB Printing Supportdevice and click Uninstall.
Now, do the following:
c. Unplug your printer and turn it off.
d. Uninstall Silhouette Studio.
e. Restart your computer.
f. Download the latest version of Silhouette Studio.
g. Right-click on the downloaded exe and click Properties. Click on the
Compatibility tab. Choose Windows 8 from the drop down menu. I also clicked the
Run this program as administrator checkbox for good measure. Click OK. (This step is important because it allows the drivers to be installed Win8 style. At least that's my theory)

h. Double-click on the exe to install Silhouette Studio. Do NOT open Silhouette Studio at the end.
I. Open the folder where you installed Silhouette Studio. It should be in a directory like this:
C:\Program Files (x86)\Silhouette America\Silhouette Studio. Right-click on
Silhouette Studio.exe and click Properties. Follow the instructions in
step g to run Silhouette Studio in compatibility mode. This step may not be necessary, but I figured it wouldn't hurt.\
J. Startup Silhouette Studio.
K. Connect your Silhouette printer to your computer via USB and turn it on. You should be able to connect from Silhouette Studio. If you like, open
Device Manager again (see step a above). You should see
USB Printing Support this time WITHOUT the yellow exclamation point. Yay!!!
November 20, 2016 Update:
The last time I tried to use my Silhouette, I had the USB Connection problem again, even after having done everything above. I think I must have just gotten lucky. This sequence posted on the
FAQ on the Silhouette America site ultimately solved my problem:
- Close the Silhouette Studio® software Power off the Silhouette cutting machine
- Disconnect the USB cable from both the Silhouette cutting machine and the computer
- Disconnect the power cable from the Silhouette cutting machine
- Re-open the Silhouette Studio® software
- Select the Send to Silhouette button
- Firmly plug in and power on the Silhouette cutting machine
- Firmly connect the USB cable directly to the machine AND directly to the computer (bypassing any USB hubs) NOTE: All connections should be made using Silhouette cables. Other cables are not guaranteed to be compatible with the Silhouette cutting machines
- If a proper connection is achieved, the Send to Silhouette screen should shortly show a READY status.
Happy cutting!