If by PC you mean Windows PC, then your microSD card is still recognized by Windows at the hardware level, but Windows Explorer cannot see it most likely because the Raspberry Pi Imager has changed the partition table so that it no longer has a Windows drive letter assigned.
FIX: Use Windows Disk Management to Assign a Drive Letter
If Windows stripped the drive letter after writing the image, you can manually assign a new one:
STEP 1 of 6: Press Win + x keys, and in pop=up menu click “Disk Management”
STEP 2 of 6: In the “Disk Management” window opened, scroll down and locate your microSD card by its capacity (e.g., 8GB, 16GB, 32GB, 64GB). Be careful NOT to select your main system drive.