Csdrhrt

To get a ^ (caret) character, I have to press the ^ key two times. The first time, nothing happens, the second time two ^ appearing. So I have to delete the second.

Same behaviour when I want to print a single ´ (apostrophe) or a single ` (backtick)

Why I have to press keys two times to get the ^ or ´ or `

You have an International keyboard layout set for your keyboard (probably United States-International keyboard layout - but there are others).

With this keyboard layout the ^ keystroke becomes a modifier to enabling entering of special characters.

To get a single ^ character you will need to type ^+Space.

Alternatively change the keyboard layout to the appropriate non-international version.

See Add a keyboard layout for more information.

Typing Diacritics And Special Characters

Type International and Special Characters using the right Alt key or the following modifier keys: Apostrophe ('), Accent Grave (`), Quotation Mark ("), Tilde (~), and Circumflex (^).

To type just the modifier key by itself, type Space following the modifier key.

Source Microsoft Keyboards - English (US-International)
Typing Diacritics And Special Characters

How to use the United States-International keyboard layout

Creating international characters

When you press the APOSTROPHE (') key, QUOTATION MARK (") key,
ACCENT GRAVE (`) key, TILDE (~) key, or ACCENT CIRCUMFLEX,. also
called the CARET key, (^) key, nothing is displayed on the screen
until you press a second key:

• If you press one of the letters designated as eligible to receive an accent mark, the accented version of the letter appears.


• If you press the key of a character that is not eligible to receive an accent mark, two separate characters appear.


• If you press the space bar, the symbol (apostrophe, quotation mark, accent grave, tilde, accent circumflex or caret) is displayed by
  itself.

Source How to use the United States-International keyboard layout in Windows 7, in Windows Vista, and in Windows XP

How to change your keyboard layout

To configure your keyboard to use a different language or keyboard layout, use the appropriate method for your version of Windows.

Note: These methods use the Canadian French keyboard layout as an example.

Windows 7 or Windows Vista

1. Click Start Start button, type intl.cpl in the Start Search box, and then press ENTER.


2. On the Keyboards and Language tab, click Change keyboards.


3. Click Add.


4. Expand the language that you want. For example, expand French (Canada).


5. Expand Keyboard list, click to select the Canadian French check box, and then click OK.


6. In the options, click View Layout to compare the layout with the actual keyboard.


7. In the Default input language list, click French (Canada) – Canadian French, and then click OK two times.


8. In the Regional and Language Options dialog box, click OK.
   Note The Language bar appears on the taskbar. When you rest the mouse pointer over this bar, a tooltip appears that describes the
   active keyboard layout.


9. Click the Language bar, and then click FR French (Canada).

Windows XP

1. Click Start , type intl.cpl in the Run box, and then press ENTER.


2. On the Languages tab, click Details.


3. Under Installed services, click Add.


4. In the Input language list, select the language that you want. For example, select French (Canada) .


5. In the Keyboard layout/IME list, click Canadian French, and then click OK .


6. In the Select one of the installed input languages to use when you start your computer list, click French (Canada) – Canadian French,
   and then click OK.


7. In the Regional and Language Options dialog box, click OK.
   Note The Language bar appears on the taskbar. When you rest the mouse pointer over this bar, a tooltip appears that describes the
   active keyboard layout.


8. Click the Language bar, and then click French (Canada).

How to make sure that the selected layout matches the keyboard

Windows 7 or Windows Vista

1. Click Start, type osk in the Start Search box, and then press ENTER.


2. Match the keyboard on the screen with the physical keyboard to make sure that the layout matches.


3. To check the uppercase characters, click the shift key on the keyboard or on the screen, and match the characters printed on the
   keyboard.

Windows XP

1. Click Start, type osk in the Run box, and then press ENTER.


2. Match the keyboard on the screen with the physical keyboard to make sure that the layout matches.


3. To check the uppercase characters, click the shift key on the keyboard or on the screen, and match the characters printed on the
   keyboard.

Source How to change your keyboard layout