Make sure all important files are backed up outside of PC. May need to reload whichever OS your on, Win10 or 11? Download Windows 10 to an 8GB (or more) flashdrive formatted to FAT32.  If you have Win11, Download Windows 11.  When reloading, a window ask, Which partition?  Delete all previous partitions.  When you click on install all, it will automatically create the appropriate partitions. Another window will eventually ask for product key.  Click on "I do not have a product key."  Win10 will then get the product key imbedded in BIOS and finish install.  Will need to reactivate online. There is also:  Download Windows 10 Disc Image (ISO File)  When downloading, it should automatically make the flash drive bootable.
My pc has not been able to detect my headphone's microphone and I don't understand why. The headphones have a combo jack but I can't use them because my pc only has one headphone jack. My pc is an OptiPlex 5070 and if there's a reason why it's not working please let me know.
Headset mic not working OptiPlex 5070