Have you left a CD/DVD in the drive or have any external drives plugged in ?
Did you reinstall Avira ?
While there have been negative reports about Avast, I haven't seen anything about Avira.
When uninstalling an AV program it is best to use it's Uninstaller.
There may be residue of the program in the registry, but I think reinstalling it rather than digging through the registry for any bits should be the first thing to try.
It's difficult to know what has caused this black screen and would have to be quite a coincidence for your graphics to have gone down when you uninstalled Avira.
Did you manage to replicate the error code for the restore point failure or try your restore points in Safe Mode ?
There are a couple of cmds you could try to see if they get you back up and they are -
bootrec.exe /fixmbr
bootrec.exe /rebuildbcd
shutdown /r /t 00
and see if there's any improvement after the reboot.
You could try Windows own tools to see if they work in Safe Mode by clicking on the Start button - Settings - Update & Security - Recovery - Restart Now but that may just boot you back into a black screen in normal mode.
I've forgot to ask - what are you using to post on ?
I assume the machine that has the problem is a desktop ?
I'm not sure if Event Viewer is available in Safe Mode without trying it, but that should have something recorded - ignore any Critical Event ID 41 as they just relate to any power shutdowns - click on Error then on Show All Instances of This Event in the lower right pane and then check recent time stamped errors.
Hello again my friend, thank you, really, for your attention
i´m going to answer in the order of your questions
I don´t have any drives plug in or cd/dvd;
I din´t reinstall Avira, instead i uninstall also avast, i did everything in Safe Mode environment;
The error code for the restore point failure is 0x81000201, i have 14 restore points, all of them give me this error, that they are damaged....;
I didn´t try the cmds yet, i´m running malwarebytes and tdskiller to see if something pops up, then i would try the cmds, i was also thinking in the "reset this pc" option, but i´m afraid of losing data...i manage to create a windows 10 iso in Safe Mode environment, i´m going to try to install windows again without losing data....i only hope that this don´t give me an error like the one before, that he could not continue with the reset, but i was running it trough usb stick and not from the hard drive, and also it was the newest version, the version that i have on the notebook is an upgrade version;
I didn´t understand this question "I've forgot to ask - what are you using to post on ?"
Regarding the event viewer, i have several event IDs, like this ones:
10005 - DCOM error 1084
55 - this one talks about MFT, file reference 0x9000000000009, it´s impossible to know the name of the file
8200 - this one refers to the system restore
3 - readyboot stopped 0xC0000188
701 - service control manager
7001 - service control manager
3095 - Netlogon
121 - 0x80004004
7023 - service control manager
7043 - service control manager
10010 - DCOM
1000 - explorer.exe error - 0x55c9b75e - 0xc0000005 - 0x00129e19 - 0xeec - 0x01d254ef067eaacf
214 - appreadiness
thank you once again