Thank you for posting,
Balazs Lengyak, I understood in your specific case the SSD came with the laptop and therefore as it is O.E.M. provided we strongly suggest you to contact the computer manufacturer for assistance.
For everybody else, you may want to double check the Intel® SSD 520 is connected to the Intel® SATA controller in AHCI mode (not RAID). Just to verify that your Intel® SSD is properly detected by your SATA controller you may open Device Manager (Control Panel), expand Disk drives, double click the Intel® SSD listed, in the properties window go to the last tab, Details, then choose Hardware Ids in the dropdown, the value should start withIDE\…in the first lines.
By the way, has anyone tested the SSD with a different system (not Lenovo)?
In case the issue persists you may contact your local Intel® support team: