How to start Taskmanager on boot and minimized

In Win8.1 I managed to have at boot a txt files and also minimized, but I can't do the same with Taskmanager.
I have both the shortcut in C:\Users\Utu\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup
What I'm missing?

Create a text file with Notepad.
Enter this line in it : start /min taskmgr
Save it or rename the file as StartTM.bat (or anything you want as long as the extension is .bat)

You can either place this file directly in the startup directory you wrote above. Or create a shortcut linking to the .bat file.

It starts the TaskManager (taskmgr) and minimizes it just like you asked.

I've attached the batch file if you can't be bothered creating it by yourself.

Or, you can simply create a shortcut to TM on your desktop, then drag and drop the shortcut into your Start menu's Startup folder. No need to mess with notepad or .bat files.

1. Right-click on a blank space on your desktop, and select New > Shortcut,
2. In the location text box, enter: taskmgr and click Next,
3. Type/edit the name for this shortcut and click Finish.
4. Right-click on the shortcut and select Properties, then in the Run section, change it to Minimized, then click OK.
5. Drag and Drop or Cut and Paste the shortcut into the Startup folder.

And you are done. Next time you boot, TM will start and minimize to your System Tray/Notification Area. Note, it may be hide so you may need to click the little up arrow to view hidden icons and from there, you can change how it is displayed.

Curious why you would want to do this?

I tried all the options and it works only the one with the .bat, but it doesn't put TM in tray as when I minimize it myself (I have the 'minimize in tray' option) but it remains minimized and visible on the bar (by the way in Win7 it worked flawlessly).
@Ztruker
I always want to know if the CPU is somewhat high and look also at some history of it in the graphs.

You can use a replacement like Process Hacker, which works like it

or Compact Tray Meter: CPU, RAM & Disk Drives Monitoring Utility.

Solved for Windows 10; Probably also works for Windows 8

In Windows 7, I could easily start Task Manager at login by simply placing a shortcut to taskmgr.exe in my Startup folder and configuring the shortcut to start the program minimized. This method does not work in Windows 10 and I suspect it does not work in Windows 8/8.1 either (I no longer have Windows 8 or 8.1).

What I wanted is to have Task Manager start minimized automatically at login and to be placed in the System Tray without showing up on the Task Bar.

To solve this problem, I created a short custom Auto Hot Key (AHK) script, compiled it and placed a shortcut to the compiled script in my Startup folder.

In Task Manager, it is also important to enable the option to "Hide When Minimized".

I have attached a zip file to this post; it contains the source AHK script and the compiled version (.exe). You only really need the compiled version (.exe). The source AHK script is only needed if you want to make your own modifications (you will then also need to get the Auto Hot Key program itself and/or SciTE4AutoHotkey [highly recommended if you are going to work with AHK scripts]).

Let me know how this works for you.