Now there is another issue here, if your computer recognizes smaller or lower memory SD cards such as 1 GB or 2GB but fails to read a 4 GB, 8 GB or higher SDHC Card then your computer’s internal reader is not SDHC compliant. See if the SD card is working on other PC and if it is then this means the problem is only on your PC.
Now the SD card may not be detected in both the internal SD card Reader or USB SD Card Reader as we have already discussed that this is a software issue, so the only way to verify this is to try to access the SD card in another PC. In most cases, the issue is caused because of outdated, corrupt or incompatible drivers, hardware issues, device issue etc.
Fix SD Card not Recognized by PC: If your SD card is not recognized by your PC then the problem may be related to drivers.
