My sund device wnt show up anywhere n my system(cmpaq evo usdt)

You should first check you have not accidentally muted it in both windows and on the speakers itself. Next go into Device Manager and check the sound driver is installed (no yellow exclamation marks can be seen).
If this has not resolved the problem then it is probably your soundcard. If you soundcard is integrated onto the motherboard then there may be further defects.
Check what internal ports you have free, there should be some long ports called PCI or PCI-e (not ports in line with the RAM). You can then buy a PCI/PCI-e sound card and it will just clip into the slots.
Hope this helps,
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