Pressing <ALT>+<ARROW_KEYS> in Visual Studio editor writes single ASCII character

Question

I am using VS2013 as my IDE and ever since I installed it acts very oddly when pressing ALT and any of the ARROW keys. I use ALT+LEFT and ALT+RIGHT to navigate backward/forward which works in principal but once VS completes the jump it writes out a single character.

This is before the jump:

This is after the jump/after pressing ALT+LEFT:

Those are the characters that are being written:

• ALT+UP: ◘
• ALT+RIGHT: ♠
• ALT+DOWN: ☻
• ALT+LEFT: ♦

I am using VS2013 at work as well all the time and I have never seen this before. I know that pressing ALT+NUMPAD_KEYS produces ASCII characters but why is that happening for my arrow keys and only in VS? Apparently ALT+UP for me is the same as pressing ALT+6 (http://www.irongeek.com/alt-numpad-ascii-key-combos-and-chart.html). I actually swapped out my keyboard to see if its got anything to do with that. No joy.

Any ideas?

Update 1:
Looks like this fellow has a similar issue but with Eclipse on Windows:
https://superuser.com/questions/668394/turn-off-alt-numeric-keypad-ascii-symbol-insertion
Sadly no answers to his post.

Update 2/Solution:

As per the comment of 'Hans Passant' I found a solution. See below for details.

Sturm

Does the same thing happen if you push the keys in notepad? – Rubberneck

Yes. Pressing ALT+RIGHT and ALT+NUMPAD_6 yields the same character in VS. – Sturm

Good. Then the problem is not in Visual Studio, but some other application/windows settings. – Rubberneck

Shouldnt it be the other way around? Because when pressing ALT+RIGHT only in VS it results in this ASCII character. I can reproduce it anywhere else. – Sturm

This is an environmental problem of course, you've got some kind of keyboard hook installed that has a bug that turns cursor keys into keypad keys. It fumbles the scan code. Could be something nasty btw. You could use Task Manager, Processes tab and start killing processes to find the evil-doer. – Lordly

github.com/Microsoft/vscode/issues/22364 – Prelect

Answer 1

I have found the cause thanks to Hans Passant.

I did a diagnostic boot and discovered the issue even then still persisted. I then went on to kill all remaining processes until I struck gold:

With this process gone ALT+ARROW_KEYS don't trigger ASCII symbol insertion anymore. I ended up doing two things in total to get rid of this process:

1. Reinstalled .NET Framework 4.5.1
2. Renamed/Removed this file: C:\Windows\Microsoft.NET\Framework\v2.0.50727\RegSvcs.exe

On booting into Windows there are neither errors pertaining to that particular executable nor have I noticed any other malfunctions. Just to be sure, I ran a couple of virus/malware removal tools. They all came up with no threats.

Sturm