You installed, not upgraded, a fresh copy of Windows 8 on the Dell Vostro 3300 notebook. Everything seems to be working fine except the SD card reader. If you put in a SD card into the reader, it does not appear as a drive in Windows Explorer.
The Dell Vostro 3300 uses the Realtek RTS5138 USB controller for the SD card reader. Windows 8 does not seem to ship with the driver for this controller. Go to the Support section of the Dell webpage for Vostro 3300. Find the Realtek-Driver under the Chipset section, download it and install it. Restart Windows and your SD card should work now.
Tried with: Windows 8 Pro