Check applied group policies

Run GUI Resultans Set of Policy - rsop.msc
Command line user policies: gpresult /Scope User /v
Computer policies: gpresult /Scope Computer /v

Source: How-To-Geek

"General access denied error’ (0x80070005)" when starting Hyper-V VM

Every Hyper-V virtual machines has a unique Virtual Machine ID (SID). If the Virtual Machine SID is missing from the security permissions on the .vhd or .avhd file, the virtual machine does not start.

icacls "D:\Virtual Hard Disks\VM.vhdx" /grant "NT VIRTUAL MACHINE\12345678-975B-469D-9A70-A31DA482AF2F":(F)

Run Powershell on remote server

Allow remote powershell: Enable-PSRemoting -Force
Open session to remote server: Enter-PSSession -ComputerName <remote server> -Credential administrator

Source: HowToGeek.com

Fix replication between DC and RODC

Symptoms: Sysvol and Netlogon shares may be missing;
                   nltest /server:<DC-NAME> /dsgetdc:<DOMAIN> /gc /force shows that RODC is active DC

Check for errors: DCDIAG /TEST:DNS and DCDIAG /CheckSecurityError
 
If replication between DC and RODC is broken and repadmin /syncall does not help - you can manually set DC replica as authoritative.

Open Regedit HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NtFrs\Parameters\Backup/Restore\Process at Startup
Set BurFlags hex value to D4 - This registry value marks the FRS replica as authoritative.
Restart the File Replication Service

Source: KB316790

Windows7 connect to wifi before login

You cannot log in windows 7 with domain user because wireless is not connected on logon screen. This feature is available only on Windows 8, 8.1, 10.

Workaround:
1. Open REGEDIT HKLM\Software\Microsoft\Windows\CurrentVersion\Run

2. Add new string value with any name you like. For example WiFiAutoconnect

3. Set value: %comspec% /c netsh wlan connect name="MyWiFi" where MyWiFi is your wireless profile name.

Find nonregular character in text file

Open file with Notepad++ -> Find
Enable regular expression.
Search for [^\x00-\x7F]+

Reset windows network state

Reset WINSOCK entries to installation defaults : netsh winsock reset catalog (change static ip to dhcp)
Reset TCP/IP stack to installation defaults : netsh int ip reset reset.log
Flush DNS resolver cache : ipconfig /flushdns 
Renew DNS client registration and refresh DHCP leases : ipconfig /registerdns 
Flush routing table : route /f (reboot required)