Hi,
I hadn't heard of this browser either; it's Russian based, and has generally safe ratings. Been out for 4 years or so. Personally, I am very careful of any browsers developed overseas and take extra precautions before using. It's a good idea to stick with you original browser and install this Yandex on a 2nd computer and test it for awhile before you switch over to it whole hog.
Also, hope you made a System Restore point prior to installing. You should know that a lot of foreign coded apps such as this bypass the generation of an automatic restore point during the installation program to make the program install size minimalistic. Doing this relies on the fact that your machine has System Restore enabled and running. Most Win7 machines have this feature (System Restore) disabled by default, as that's how Microsoft has it setup unless an OEM computer maker such as Dell or HP changes that in their SLI image. That means that if your Yandex didn't make a System Restore point during the install and you've never enabled System Restore--it's not going to have rollback capability.
And this means you are vulnerable to whatever bugs or problems this new browser presents,
unless you have good backups, preferably folder/volume backups to external media (external HDD, flash drive, DVD discs), even better Image backups such as Macrium, Acronis, EASETodo. Most browsers, especially IE11 and Edge (both from Microsoft) are integrated into the Windows OS kernel; this means that when they get scrambled by a badly behaving or poorly coded program, Windows gets scrambled as well and repairs are problematic and generally require professional help to fix.
I'm not saying you shouldn't use it, but there are a number of Red Flags that Users should be looking for when installing a new program such as a new browser that can have catastrophic effect on your Windows if not properly designed. One of those Red Flags is the System Restore during installation.
Did your Yandex set a System Restore point for you, or tell you it was doing so, or ask you permission to do so? If not, that's a big enough Red Flag to keep me from using that on any of my production machines (daily use).
Best of luck,
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