“First of all, the 128GB SSD is chopped into seven separate partitions. Here’s what each of those partitions contains:
1000 MB (Recovery Partition) – This partition contains Windows Recovery Environment tools and utilities, allowing you to repair problems that affect the system drive. The Lenovo partition seems considerably bigger than it needs to be. The equivalent partition is 600MB on my ASUS notebook.
260 MB (EFI System Partition) – This partition (details here) contains boot files for a GPT disk. On my ASUS system, this partition is slightly smaller at 200MB.
1000 MB (OEM Partition) – I have no idea what if anything is stored here (bundled programs, maybe?), and I wasn’t able to open it or assign a drive letter using the display model. The ASUS machine has no corresponding partition.
63.91 GB (Windows 8_OS) – This is the system drive (C:). After all the bundled software, it has only 42.22GB available for user data storage.
25.00 GB (LENOVO) – This is drive D:. It’s accessible in File Explorer, so you could use it for data storage. Apparently Lenovo created this enormous volume solely to hold about 1.7 GB of driver files.
8.00 GB (unlabeled Primary Partition) – This is another mysterious disk space thief. It appears to be empty and it has no drive letter.
20.00 GB (Recovery Partition) – This partition contains the recovery image that would be restored to the system drive if you use the Refresh or Reset option in Windows 8. This is the correct location for this partition, which is roughly the same size on the ASUS machine.”