How to enable disabled account in windows if you could not login.

Almost all the way to enable login in windows assume that you can log in to windows, but what if you cannot? What to do if you accidentally locked you computer?
Solution is pretty simple: Boot from windows CD or USB drive.
When you see windows setup screen press "Shift" + "F10", this open command prompt.
Then you need to replace utilman.exe file to cmd.exe to do this enter following commands:

copy d:\windows\system32\utilman.exe d:\
copy /y d:\windows\system32\cmd.exe d:\windows\system32\utilman.exe

Usually windows is located on drive d: if it is located in different drive correct commands accordingly.

Now type:

wpeutil reboot

after PC reboots and you see login screen press "Easy Of Access" icon and command prompt opens.

Now you can enable disabled users. For example if you want to enable disabled builtin administrator:

net user Administrator /active:yes

Now reboot computer and try to login with administrator account.

User profile service failed to sign in

Logon to windows(in my case win8.1) failed with error "user profile service failed to sign in", "user profile cannot be loaded". I was able to create user, but it was impossible to login with that user. Users with already created profiles can login without any problem.
After browsing internet for one day no solution was found. I check system integrity (sfc /scannow), check disk for errors (chkdsk), made restore of system files (dism utility), check registry and etc. All was unsuccessful. The problem was that something was wrong with default profile permissions. To fix this issue go to c:\Users\Default right click on that folder, select "properties"->"security"->"advanced"->"change permissions"->select checkbox "replace all child object permission entries from this object"  and click "OK"

Then try to login.

How to remove unused USB serial ports in windows and change port numbers

Sometimes when you connect usb to serial adapter to your pc it gets com number with very high numbers. Not every software can handle that big port numbers. For example some programs cannot work with port numbers higher than com20. So if 20 com ports are in use it is impossible to use that software.  That happens because every time you plug in new USB to serial adapter it gets new com port number, and even if you do not use it anymore port is marked as "in use".
To delete these ports open elevated command prompt: find cmd, right click on it and select "run as administrator".
Then type:

set DEVMGR_SHOW_NONPRESENT_DEVICES=1

after that run device manager:

devmgmt.msc

Enable "Show hidden devices" in the "View" menu, and uninstall grayed-out COM ports

After that you can change your device com port number: right click on it, select properties, then  advanced setting.