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

Question

I use VS2013 as my IDE, and since I installed it, it is very strange when you press ALT and any ARROW keys. I use ALT + LEFT and ALT + RIGHT to move backward / forward, which works in principle, but as soon as VS completes the jump, it writes out one character.

This is before the jump:

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

These are the characters that are written:

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

I use VS2013 all the time at work, and I've never seen this before. I know that pressing ALT + NUMPAD_KEYS creates ASCII characters, but why does this happen for my arrow keys and only in VS? Apparently ALT + UP is the same for me as pressing ALT + 6 ( http://www.irongeek.com/alt-numpad-ascii-key-combos-and-chart.html ). I actually changed my keyboard to find out if this is related to this. There is no joy.

Any ideas?

Update 1:
This guy seems to have a similar problem, but with Eclipse on Windows:
https://superuser.com/questions/668394/turn-off-alt-numeric-keypad-ascii-symbol-insertion
Unfortunately, there are no answers to his post.

Update 2 / Solution:

According to the "Hans Passant" comment , I found a solution. See below for more details .

Answer 1

I found the reason thanks to Hans Passant.

I did a diagnostic download and found the problem, although I continued it. Then I continued to kill all the remaining processes until I hit gold:

When this process proceeds, ALT + ARROW_KEYS will no longer trigger the insertion of ASCII characters. In the end, I did two things to get rid of this process:

• Reinstalled .NET Framework 4.5.1
• Renamed / Deleted this file: C: \ Windows \ Microsoft.NET \ Framework \ v2.0.50727 \ RegSvcs.exe

When booting into Windows, there are no errors related to this particular executable file, and I did not notice any other malfunctions. To be sure, I launched a couple of virus and malware removal tools. All of them did not threaten.