The quick answer is not really, but let me explain in more detail.
IF you have realtek audio chip that supports this on your board you can follow this video link to get stereo (2.0) sound to both the TV and the speaker set: http

/youtu.be/Jb_VU8LfQZA.
The other possibility is IF your TV actually allows you to output audio to speakers AND play on the front speakers at the same time.
Now doing this will likely sound like crap because the "rear" speaker set will be much louder and more pronounced then the TV speakers. You also have to worry about split second delay that could sound really annoying hearing it at both locations.
In a true 5.1 surround setup you have your L/R speakers for music and foreground sound effects, center for voice/dialog (this is the most important speaker), subwoofer provides low frequency sounds , and rear surround speakers are for background noise.
If you tried to use your 2.1 system as actual surround speakers then the subwoofer would get all the wrong bass notes and sound really odd, not to mention the rear speakers would be much more powerful and pronounced over the front speakers.
The even bigger problem is that you are missing the center speaker which is what gives you the dialect of what everyone is saying.
Thus if you tried to set this up as an actual surround sound then you would not hear the actors talking at all and the rest of it would also sound like crap.
At the end of the day, with only your current equipment your best audio quality option is to just output to the PC speakers instead of the TV because the PC speakers are better and are at least 2.1 (even if the subwoofer is undersized for the room). The most inexpensive option is to just get a 5.1 set of PC speakers if you are willing to buy equipment, naturally the best option is an actual home theater system.