Quartus II Programmer : Unable to detect hardware

[Altera_Forum]

Hello, 

 I am using Quartus II 15.0 (64 bits) and I have been using the DE0-nano board for a while, without any trouble. I have stopped using the board for a few months until today. But today, Quartus II programmer doesn't detect any hardware anymore.  

• I tried 4 different boards; 
• It is working perfectly on a co-worker's computer. 

  I had to install Quartus II 11.0 (32 and 64 bits) to make changes to an old project, so I have now 2 distincts versions installed. A few extra info:  

• I have a valid Quartus II license; 
• I attached an image displaying a crazy 770Go for Quartus 11.0 program. 

  I have no clue about where to start to investigate. Does anyone have experienced such case?  Thank you for your time,  Damien

[Altera_Forum]

I have frequent problems with Q15.1 detecting hardware - be that dev boards or USB-Blasters. This is despite one or more 'Altera USB-Blaster' entries in device manager. Disconnecting/re-connecting sometimes works. Rebooting generally fixes it. Reverting to Q14.1 always fixes it. 

 Cheers, Alex

[Altera_Forum]

What is the QUARTUS_ROOTDIR environment variable set as? Is it still pointing to the Q15 directory, or has it changed to be the Q11 one?

[Altera_Forum]

You should try launching the Programmer from Quartus 15.0 directory. My programmer executable is here: C:\Altera\15.1\quartus\bin64\quartus_pgmw.exe Your executable should be similar other than 15.1 should be 15.0. Good luck, Mo

[LegoTechniker]

Hi,

I found out by accident that missing .net ASP services seemed to be the cause. Someone with more knowledge can possibly confirm that this was really the cause...

You can find it in the additional Windows services.