Streamed music sounds awful in my system and I don't know why ....

You can modify the pc diy route as some above have mentioned, you can also go lower, medium grade off the shelf streamer, and then there are top of line streamers. My choice is top of line streamer budget allowing. Streams should be virtually indistinguishable from cd over transport or cd rips, you'll know you've arrived when this is your experience.

a few points.  While i agree that the problems re likely with WMP and the PC, i want to re-iterate where the problems likely lie. Not with the simple fact that you are using a PC -- but with two things:

1. The configuration settings, some of which may be very hard to optimize

2. With the electrical (ground) noise

Both of these can be ficed, but most wont have either the expertise or the inclination to do so. On a mac you can use bitperfect and the configuration issues are solved.  Gond isolation is more of a problem, although on battery power my macbookpro was more or less fine.

Many have suggested Roon.  I love roon, and also hate roon. Note that you will still have the ground noise problem if you connect your roon PC directly to your DAC.

Roon has also just made major changes that i find a real problem. They discontinued support for most operating systems aside form the very atest - making most of my units obsolete even as casual remotes.  They also have made it so that you cannot play your own local library unless you have an active broadband internet connection.  You heard me right.  So yea, its great, but its also nto the most customer friendly company on earth. This is all very new BTW.  Beware.

I do think that software solutions liek Roon or audirvahna are fare more modern and long-term than some costly streamer-in-a box (which is almost certainly a raspberry Pi computer inside a fancy box with a good power supply and isolation).

@esarhaddon

This has nothing to do with bits. The bits arrive just fine.  The problem is ground noise and pre-processing of the bits.  Most media players do digital manipulatino of the signal to put it on the media bus, and then spit it out. Most also do some level manipulation, including digital volume control, which rob you of resolution. As numbers are multiplied (which is how volume control is achieved) there are remainders nad truncation's. You can very esily get down into 10-12 bits effective resolution.

It matters not if its a $10,000 gaming PC or a 10 year old core duo.  Same problem exists.

@itsjustme The raise a number of great points:

Basically it's all about the noise from a computer. Fighting is possible but for those who computers aren't their passion, it's not worth the fight. Get a low power single-purpose device with a simple OS and w/o a million processes running that aren't in support of audio(aka. a streamer).

Not to quibble but the other side of this statement:

They also have made it so that you cannot play your own local library unless you have an active broadband internet connection. 

That's so they can give you all the fantastic metadata, artist links, biographies etc. For any victims who've ripped CDs in iTunes and lost album art...well Roon is your savior. I'm sure if enough people complain about it, Roon will provide an option to turn off internet connection required, but IMHE, it's a benefit even when listening to my own library. More often than not, their metadata and supplements are better than what's on the files. YMMV Cheers,

Spencer

On the quibble, i understand that they enhance music with metadata (however, its not as great as they claim - not i'm a user since pretty much day #1) but there is no enhancement when my music does not play at all.  Sure, give me the full experience with internet, but don't block the core of my system.

I have already complained, as have many more, and note they slammed the door on it ever changing.  So the answer as you say is "enough people"....apparently not enough today.  So buyer beware.

Anyway - to the OP. Figure out the exact configuration that you are streaming. Its often hard ot find in a PC.  Next, isolate. Even my roon core is run on a custom, linear, low noise power supply of my own design.  beyond most peole's ability, but buying one is just a few $100.

Don't just react to "PC bad".  PC not bad, PC just opens pandora's box.