So, step by step, what did you do and where did you get stuck.
W10 - a tablet PC - feeds my DAC via USB. I want it to remain quiet / do as little work as possible. I can install JRiver (trial) on this W10. I can adjust Audio settings and play local files on W10. I can transcode/upsample in DSP Studio on W10. Contrary to what one may read on the web, I think that JRiver perhaps plays better (cf. SQ) than foobar2000 doing exactly the same job, and that is why I want to persevere with JRiver.
Turning to streaming instead of single PC:
I can get foobar (foo_upnp installed) on W10 (in listening room) to play music *streamed from* W7 (a hi-spec stable workhorse machine not in the listening room) either from Minimserver (flac:wav24;88 for my Linn AV 5103's integral DAC) - or from foobar Media Server on W7 - in either case with the stream *already transcoded/upsampled* on W7.
I want JRiver on W7 to do the same thing as an alternative to Minim/foobar.
Using JRiver MC on W10, I can read W7's Library and play W7's files - Library Server mode as described by csimon - but any transcoding/upsampling is done on W10 this way.
Hence - there is a distinction - wrt my needs - between JRiver in Library Server mode and DLNA mode.
I need W7 as JRiver Server, streaming to W10 *transcoding/upsampling on W7* with W10 as Control Point (or Renderer if no Control Point is necessary - NB: foobar's UPnP Browser on W10 gives full access to, and play-control of, W7's Library, without its "Media Renderer" having to be started - and without use of its "UPnP Controller").
In JRiver MC, on both W7 and W10, I have the Media Network settings checked so that I can see Servers on W7 and W10 mutually.
What other settings (Audio / Media Network) are required such that *on W10* I can select and play flacs stored on W7 - but in DLNA mode - such that *transcoding/upsampling happens on W7* ...
... just like I can do so easily in foobar ...
... but I want the SQ enhancement I (think I ;-) hear in JRiver (fuller - more analogue-like).
TIA
Addendum - I have confirmed that I can - *operating in JRiver's MC on W7* - send W7's music files to W10's Renderer appearing under W7's "Playing Now" - where the transcoding/upsampling happens as it should - i.e. as set in "Add or Configure DLNA Servers" on W7 ...
The final *vital* missing step is to be able to perform the same operation/otherwise control play in JRiver MC on W10.
Addendum #2 - "Playing Now"/"Overview" in JRiver's MC on W7 shows the full queue of files being streamed to W10 as described immediately above. On W10 in Playing Overview, however, I can see only the present playing file and - if streaming has progressed sufficiently - the next. I can advance to the next on W10, but can see no more of the queued files, nor operate on them. I can, however, see W7's Library. I can even send W7 files to the same Playing Now queue as those files being streamed - but such files are played in Library Server mode not DLNA mode - i.e., at the sampling rate set in DSP Studio on W10 not the sampling rate set in ""Add or Configure DLNA Servers" on W7.
As an aside - I am not positively struck by SQ in streaming mode when successfully achieved on W7 (vs. W10 at my coffee table - being the main sticking point here) - although these are only first impressions. I am likely to give up on the idea of streaming as I had hoped using JRiver, and may consider purchasing the software if I remain convinced that SQ in single PC mode is better than that via foobar whether single PC mode or streaming. I can see a Cognitive Dissonance assault - possibly even a microRendu - coming my way. :-)