[EDIT: completely revised answer]
Some observations, two solutions and a warning regarding Registry changes. The observations will improve your understanding and are necessary for the differential diagnosis of your problem.
- The problem occurred/occurs in in principle all Win versions: XP, Vista, 7, 8 and 10. I read that here and on other forums.
- The problem occurs on laptops and desktops.
- The problem is reported to occur on Lenovo and Dell machines, although in many reports no brand is mentioned. (If your machine is a different brand, please leave a comment.)
- There is a difference between sleep (= standby) and hibernation. And you might have 'Hybrid sleep' on your machine. For the whole story, see https://www.howtogeek.com/102897/whats-the-difference-between-sleep-and-hibernate-in-windows/.
- There are 4 circumstances under which you have to enter your Windows password, each with their own indication above the password field:
- After the screen was locked. Indication: 'Locked'.
- After you rebooted. Indication: none.
- After you logged off (which also means that all programs were closed). Indication: none.
- After you switched users. Indication: in case of only one user: 'Logged on' (yes, 'on'); in case of multiple users, that may differ (I cannot test that).
See when exactly your problem occurs, by means of the indication. If you do not use a password: Control panel > Power options > Left pane: 'Require a password' > select 'Require a password'. The following solutions are for the case 'Locked', which I think is the vast majority of cases. If your case is different, please leave a comment.
The two solutions are improvements of suggestions by others, here and elsewhere.
The first is a quick fix, for laptops: Control panel > Power options (or equivalent) > 'When I close the lid': Do nothing (2x). That might cure your problem, even though your laptop will not automatically wake up anymore after opening the lid.
The second is an advanced solution, for laptops and desktops: an automated cmd.exe (DOS) command that resets the character repeat rate (that's what it is called officially) to maximal, immediately after unlocking the system. Here is the How to:
A. Open Notepad and type
mode con: rate=31 delay=0. Higher than 31 is no use, delay=0 is. Save it in a Windows system folder (e.g. C:\Windows), naming it something applicable, like CharRepeatReset.bat. The .bat is a must.
B. Double-click the file and see if it resets the repeat rate. If it does, you can automate that double-clicking as follows:
- Start > Search > type: task > Task Scheduler.
- Right pane: Create task. That opens a window with the tabs General, Triggers, Actions and Conditions.
- General > Name: the name of your file without the .bat (e.g. CharRepeatReset). For now, leave all other settings on that tab as
- Triggers > New > On workstation unlock > Any user.
- Actions > New > Start a program > Browse to your .bat file.
- Conditions > De-tick 'Start the task only if the computer is on AC power'.
- Click 'OK' (no need to change anything in Settings).
Let me know how it works, here or via f [dot] conijn [at] conijnconsultancy [dot] com.
WARNING REGARDING REGISTRY CHANGES
This concerns the changes made in HKEY_CURRENT_USER\Control Panel\Accessibility\Keyboard Response, that are suggested sometimes. I tried that in several ways and it might work, but in all cases it came with serious side effects. Ranging from the processor going into overdrive to complete freezes that could only be solved with power interruption. The latter makes you loose unsaved files. So be very careful with that.