I have been messing around with my second computer for a while. I added the ssd from. My pc detected it in the BIOS but it doesnt appear in Windows installation setup . it appears in Explorer
I'd suggest you check if the SSD is in the boot priority in BIOS as well. I'd also advise you to try plugging it in the first available SATA port on the motherboard and see if that will get Windows Installation Setup to recognize it. If it still doesn't help, maybe you should try resetting BIOS or checking your motherboard/PC manufacturer's website for any BIOS/firmware update available.
Try formatting it to NTFS before you start the installer. If it's one of the newer NVME SSD's, you might also need to load drivers for it, but if it's a traditional 2.5" SATA SSD it should detect it it in most cases.
I'd suggest you check if the SSD is in the boot priority in BIOS as well. I'd also advise you to try plugging it in the first available SATA port on the motherboard and see if that will get Windows Installation Setup to recognize it. If it still doesn't help, maybe you should try resetting BIOS or checking your motherboard/PC manufacturer's website for any BIOS/firmware update available.