When intel processors appeared, those of the "i" family (i3, i5, i7), graphics "cards" built into the processor appeared. In laptops that have an Intel i3, i5 or i7 processor, you have the Intel HD graphics card and the ATI/AMD graphics card.
Since Intel graphics cards are not really graphics, they are much less powerful, hence the fact that on some computer models and some manufacturers use it in their solutions. low-end: for internet browsing or a movie (non HD), no need to have a real graphics card that kills! As they are less powerful, they also consume less energy, and in the field of portable pc, it's quite important! And that's why they're usually used when you're on the battery and when you change to the sector socket, you also have a change in the graphics card: they call it "switchable graphics."
Changing graphics cards
You should know that this option to be able to switch the switchable graphics, it is the manufacturers of your laptops that make available this function with custom drivers: if you download the official driver to update the driver of your ATI card, you can tell byebye to your ability to change graphics card depending on whether you are on battery or on sector!
The arrival of this dear Windows 10 brings its share of improvements, but also its share of problems, especially at the level of drivers! Especially since Microsoft has decided to pass the upgrade for free the first year to all owners of an official Windows 7 or 8.1!
Mine of nothing, Windows 7 dates from the end of 2009, so that at the time I write, almost 6 years that it came out! Already it is very rare when manufacturers update their software and drivers (bug, performance improvement, etc…)when your product is supported (about 2 years if I'm not mistaken), so do not dream that this support will come out and will miraculously be active for the release of Windows 10! (For those with Windows 8.1, it depends if it was W8 at the beginning, product, manufacturer, etc…)
Graphic cards and Windows 10
Since W10 is a new operating system, your drivers that were compatible with Windows 7 may become incompatible. Moreover, some AMD drivers of first-generation switchable graphics cards (ATI Mobility series 5xxx/6xxx m) simply gives a bootloop (loop restart) on Windows 10!
AMD has solved this problem with new drivers, but as I said above, you will lose the function of configure switchable graphics! As a result, you will only be able to use one of the two graphics cards and what will result, depending on the graphics card: sharp decrease in battery life if ATI card, inability to play, watch ings, watch movie in HD, etc. if Intel card.
How to have drivers up to date and keep the graphics function switchable?
By opting for the Solution Catalyst UnifL: Catalyst being the name of the management program of your graphics card ATI, and UnifL for Unified (assembled ) Leschcat (the name of the team).
So how does it work? Well it's relatively simple: basically, they take the official drivers of Intel and AMD, make food and reserve it with a program that will allow you to have the drivers up to date, but with the switch function of switch commutable graphics!
For those who don't know what "Legacy" means, by Wikipedia:
Legacy means "legacy" in English. This term is frequently used in information technology, to refer to outdated systems that are still in use.
Whether it's the very first and therefore old graphics cards or the brand new, 32bits or 64, it's no problem!
Plus it's free, continuously updated and there's support to help! On the other hand, it is in English.
The site: http://leshcatlabs.net/unifl-unified-leshcat-drivers/
The manual: http://leshcatlabs.net/manual_chm/
The download area: http://leshcatlabs.net/downloads_unfil/