Lazy_traveller, you omitted a crucial bit of information when you asked your question. That crucial bit is the word, "notebook", which you didn't mention until your reply to Hexbob6. There are settings in the user preferences to make use of a laptop possible, but personally, I don't find them very satisfactory. Based upon my own experience, I would most emphatically suggest getting an external full sized keyboard—the kind with a separate numeric keypad—and a 3 button mouse. You should be able to get both for about USD 25.00 (or up, if you're so inclined) in the US. I have both a USB keyboard, and a USB mouse, but I don't know of any reason, if you wanted, that you could not use a bluetooth keyboard or mouse. It works like a charm. If your keyboard and mouse come with separate drivers, I would be sure to make sure they are the latest versons.
As to CTRL-R on your computer not activating loop-cut in Blender, I suspect (don't know for certain, as I don't have a Lenovo Laptop) that the culprit here is that on your laptop, the key combination CTRL-R is being used to control some aspect of the hardware, so the keystroke is being filtered out, and never sent on to Blender.
If you really want to (or must, for whatever reasons) use your notebook with Blender, do a Google search for "using Blender on a laptop", find the most recent tutorial, and adjust the user preferences as indicated in the tutorial. It is even possible to bind loop-cuts to a different key combination than CTRL-R, if necessary.