Dell Optiplex 980 Desktop Internal Speaker plays & External Speakers

I have a Optiplex 980 desktop Intel 5 w/SSD and windows 7 Pro OS.
Strange thing about this computer's internal speaker that plays even with and while there are attached 2.1 speakers.
I use the Desktop's speaker icon in the sys tray at bottom right pocket of screen to adjust its volume control and then hand remote volume control on the Creative speakers.
Any ideas or recommends to rectify this problem would be appreciated. (I can go back to shop where i purchased the computer, and plan to do so, unless i find strategic fix in the meantime). But it's out of Warranty as far as online Dell's site tech recommended going in and physically removing the cable to the attached speaker from the motherboard. While that's not too difficult from the diagram she used, I didn't really feel eager to try that since it is new as far as from where i purhcased and my friend's Microsoft Certified. I desired Windows 7 and he installed that, removed Windows 10 but retail doesn't do that same courtesy which is why i chose to go to him when i needed new computer after my other desktop (TMI) was "rained on" through a leaky ceiling. There went solar keyboard too, it looked kind of funny with water in the panels. Just a little info. there that's not necessary. Sorry.
Thanks for any helpful info. if so.
BTW the computer's onboard audio's Realtek High Def. (driver).

firebred, Thank ya for your input.
Your method is identical or the same 'fix' that Dell website's tech gave for dis-engaging cable from the mobo of the internal speaker.
I guess that is the only solution, as I've projected this same topic in a couple other forums and 1 response came w/same as yours, Dell's and so it is. I don't mind the int. spkr. for the start up and shutdown sounds as far as that is and i kind of got used to adjusting both volume controls and sort of balance it out by having all 3 play.
What's a little strange about this computer's not a lot of online input or information about it like i would expect as far as straight search from Start Page (or that is, Google).

Thanks again*


kleis

Thanks for the time in taking to look at my topic and provide your ideas and i've seen this article too. You know when it comes to Bios, it's really not like my other computer's Bios, well, i mean they are all about the same but it's not like "onboard audio"s coming out anywhere. Something firebred has said echos loudly now, this is particular business computer-fied and i wasn't so aware of that when i purchased it. Mine got damaged from rain (leaky celing) and i mean it got showered. So did the solar keyboard Logitech i had and these 2 solar panels on it (it is a neat keyboard or was) the two panels when i picked it up looked or reminded me of an aqarium of ... well, there was water in both panels like not full but enough that if i took my finger alongside the panel or like when you were little and maybe on a frosted window...oh well TMI the idea was the water would run seemingly move alongside my finger as i pressed on the panel and then when i removed fingers from panel it would jump back into the little corners of the panels. :| i wasn't too happy that night. Well, anyway, a week later or the next weekend after not having a computer at all....i went to a friend's shop and we discussed what he had and i text him this issue i am having and didn't hear back. He's not like avoiding me and would gladly see me if i take computer over but i wanted to delve into Dell and find out on my own and what i can do. Now i wonder if its.... can i add a sound card to enhance or turn this into a normal computer? because some article i read, was about the corporations or people who bought this particular model/make was happy with the internal speaker as functioning loud enough for business.. well, but i need some loud music and videos....after hours. or after corporate 5 o'clock. I mean it doesn't sound too bad or for the most part, it's normal. Someone advised someone else on forum to go into Bios and disengage the ... oh what's the abbreviated.... CITES...or something like that it has to do with (i believe for gamers...gamers bought this too...hmm) but it's helped them i guess to overclock it or enable it and someone said that sound was muffled and that's when they advised about unticking those particulars in Bios and i found it alright but i kind of drifted the thought of doing that or it's not something i'm ready to go exploring right now, and if anything, i can talk to the shop guy where i bought it.
Thanks again Man!

firebird,
You are right on about the business computer line of this particular model, i just told my input about that in alphanumeric's reply to mine and i'm wondering if it is compatible for installling sound card (?) or would that make noticeable difference, etc...(?)