Hope to upgrade to Windows 10 for your laptop is practically non-existent. As others have explained Win 10 can be more trouble than it's worth. It also opens up the door for more of MS's/Big Brother's spying than any other OS to date and that is something that one truly should think about and decide whether or not further loss of what modicum of privacy computers and the internet has left is worth it to them as an individual or not. For me, personally, I will never do Win 10. I've done too much research on it and the cons (both technically and otherwise) FAR outweigh the pros.
That said, for that particular laptop, the very first thing you need to do is ascertain whether or not your laptop is 32 or 64 bit and go from there. Have you visited Lenovo's website pages for your laptop? If not, then you should. Here are the two that I could find: http://pcsupport.lenovo.com/us/en/products/laptops-and-netbooks/lenovo-g-series-laptops/lenovo-g555-notebook?c=1 and http://www.lenovo.com/shop/americas/content/pdf/notebooks/Essential/G-Series/G555%20Datasheet.pdf There may be others, you might want to do some searching of your own to see if there are, in deed others so you can visit and study them, as well.
Once you've learned as much about your laptop from Lenovo's own site, then you'll be better equipped to make the decision as to what Windows version(s) you can run on it based upon whether it is 32bit or 64bit and what drivers are available for your hardware based on the Win version it is or will be equipped with. If you've already called Lenovo for help, you may have and probably did run into the same brick wall with them that I did when I bought one of their mother boards. I wound up taking the motherboard back and exchanging it for a different brand while promising myself that I would NEVER buy ANYTHING made by Lenovo ever again. When I found out that they had acquired Motorola I was extremely disheartened.
Back to your question at hand, again, as some others have suggested, you could easily decide to go with finding your favorite version of Linux. There are flavors of it that are quite easy to use. You can try them out from a bootable CD while leaving your hard drive untouched so as to find one that you can enjoy using. Just be aware that any particular distro of Linux will run a bit slower from Live CD than it will once installed on the hard drive. Once you find the one that works the best on your hardware and for what you do with a computer, you can then make room on your hard drive for another partition to install that Distribution (or Distro) on so that you can still use Windows while learning more about using and dealing with your chosen Distro of Linux. Start your research into Linux here: https://www.linux.com/what-is-linux and here: https://distrowatch.com/ There are many other websites that tell about Linux and its various distros, so with what you learn from those two sites you can do some more research on your own to learn even more to equip yourself with the knowledge to pick the distro that is best for your hardware and usage.
As a side note, I have a desktop Compaq computer that is loaded with its native 32-bit Win XP, another computer that I built about 3 or so years ago that has Windows 7 on it and will eventually have my chosen distro of Linux in a dual boot configuration with 7 and MAYBE even XP in a triple boot configuration with 7 and Linux. I also have a Dell Latitude D630 laptop that I have PCLinuxOS (my chosen distro) installed on. Incidentally, the Dell came out originally loaded with Windows Vista. It has a dual core Intel Centrino processor and I upgraded/added some more memory and replaced the smaller hard drive a larger one. My custom desktop is my "work horse". I use the XP computer only for a couple of my favorite games that Win 7 won't run. It is not connected to the internet at all. The laptop, I only use when away from home or teaching myself more about Linux. My point is that there are many ways to make the move from one OS or version of OS to another so as to continue using a computer even after it's "too old" for Windows. Some day even Win 10 will be obsolete, so may has well learn how to deal with that now so you'll be jumps ahead of the game when it does happen.
You'll have a learning curve with Win 10, anyway, so why not use that to your advantage to learn something that could enable you to move away from Windows altogether before Win 10 goes obsolete? After all, MS has stated themselves that Win 10 will be their very last PC OS. They are moving away from the PC world into more commercial applications of their product such as automotive, telephone and other such commercial applications, anyway. So, why not get the jump on getting prepared for that day???
I have a Lenovo G555 laptop with Windows 7. Wanted to upgrade to Windows 10, but after 2, almost 3 days on and off with Microsoft support, it has finally been determined the computer is incompatible with Windows 10! While I was able to get 10 to load, the MS folks said I might have difficulties and that Windows 10 would not work smoothly. As I write this, I am rolling back to Windows 7 without even trying the Windows 10 1607 build. After trying to get an answer from Lenovo about this, their reply is in essence, "too bad." Any of your followers who have any suggestions on how to possibly get 10 on this laptop would be appreciated. A friend of mine said, "thank your blessings and move on!" Thanks for your help.
--Submitted by Larry A.

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