> I own the HDSP.
HDSPe is no product.

> Installed the newest HDSP driver
This is not a valid information, whats the driver name and what is the version number.

> Using Win 10.
This is insufficiant information, this product exists since around 5y. What version exactly ? 1909, 2004, 20H2 ?

> Where's the old driver?
Impossible to be answered as the information, that you gave, is incomplete.

Based on this thread it might be the case that your WDM settings have been reset to zero.
Then you have no WDM devices anymore in the Windows Sound Settings.
See also here:
https://forum.rme-audio.de/viewtopic.ph … 63#p153063

While you are at it, please install the "real" latest HDSPe driver, which is 4.36 (not 4.29 as you claimed).
https://rme-audio.de/downloads/driver_hdsp_win_436.zip

Always keep in mind .. if you say "no sound".
On windows there are two main possible audio signal flows
a) through ASIO driver
b) through WDM driver because Windows OS and normal Windows application do not support an ASIO driver.

Once you installed the latest driver, check in the driver settings (win desktop: bottom right: in the Windows notification area)
Number of WDM devices.
Create a WDM device for the I/O port where your monitors are connected to.
Then in the 2nd TAB set it also as speaker device.
Then you get in Windows Sound settings also a speaker device.
This Speaker Device you need to set as Windows default sound device.

I hope that this was the issue and that this will fix your problems.