I installed Windows 7 from scratch on my Lenovo X230 laptop a few years ago. One error I was never able to resolve was a missing driver for the “Base System Device”. This shows up in Device Manager with a yellow exclamation mark.
Each time I tried to update device drivers, it said “driver not found”. Recently I inserted a camera card in my laptop and I could not see it in the drive list. After doing a Google search for “lenovo X230 Windows 7 base system device driver”, I found the solution. The missing device is the Ricoh card reader.
I followed the link on this page to download the device driver:
https://forums.lenovo.com/t5/ThinkPad-X-Series-Laptops/X220-Base-System-Device-problem/td-p/2055011
I manually updated the driver for Missing “Base System Device” and it works properly now.