There are times that by mistake or our catastrophe Grub stops working (the Grub error 17, 21 and 22 are the order of the day)
Most of the time, a reinstallation of the window causes the disappearance of our beloved boot manager (Mocosoft protects us by preventing weeds from growing on our pc).
Although with a livecd and the command grub It can be solved, fortunately, there are more comfortable ways to do it.
There are versions for CD ROM, floppy and even pendrive (I plan to tell you about the latter in a future article that I have in preparation).
Its use is really simple and includes the possibility of automatically restoring grub without having to answer absolutely anything, so if you are not very busy you always have that possibility.
If someone need help to use it I invite you to use the comments to raise your problem; I will be delighted to give him a hand (around the neck 😉)