How to disable the Windows swipe-away screen lock, without disabling the password?

Yes, you can disable the lock screen without disabling authentication, using the Local Group Policy Editor. Here's how to do it:

1. Press Win+R
2. Type gpedit.msc (runs Local Group Policy Editor)
3. Navigate to: Computer Configuration > Administrative Templates > Control Panel > Personalization
4. Enable the setting: Do not display lock screen

If you do not own the "Pro" version of Windows 8/8.1/10 then you do not have access to the policy editor. You can still edit the policy, but you need to go through regedit instead. It's only slightly more complicated that way:

1. Press Win+R
2. Type regedit (runs Registry Editor)
3. Find the key: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Personalization
   • Personalization May not exist under Windows, so right click its label and select New > Key to create it
4. Right click on Personalization and select New > DWORD (32-bit) Value
5. Name the new value NoLockScreen
6. Now Right Click > Modify the new DWORD and enter 1 for the Data Value

Now, when you press Win+L, you'll be presented with the password input screen instead of the lock screen.

Thanks to Xandy in the comments for this Registry edit

For the lazy people of the world this can be run with PowerShell:

$Key = "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Personalization"
If  ( -Not ( Test-Path "Registry::$Key")){New-Item -Path "Registry::$Key" -ItemType RegistryKey -Force}
Set-ItemProperty -path "Registry::$Key" -Name "NoLockScreen" -Type "DWORD" -Value 1