Thank you very much for joining the Intel® graphics communities.
In regard to your inquiry, the option to upgrade the value of the video memory or VRAM will depend on the system you are using. Normally the option to upgrade that value is located in the BIOS, some manufacturers already assigned the maximum value to that option, some others block the feature, and in some cases the option will not show up in the BIOS so there will be no option to upgrade it. Basically it will depend on the computer that you are using so we recommend to get in contact directly with the manufacturer of it in order to try to get further details about his feature.
On the following link you will find further information about this matter:
Any further questions, please let me know.
alii98, Yes, there are some users that manage to increase the VRAM size using that method, but to answer your questions, it will be better to get in contact directly with Microsoft® to confirm that information, we do know that regedit is a very delicate command, where depending on the changes you do there, the computer could start showing some problems.
I found a link that shows some steps to increase the Video Ram for Windows® 10, but if you have the option to contact Microsoft about this matter, that will be a good thing to do:
Microsoft support site: https://support.microsoft.com/en-us/contactus/
Any questions, please let me know.