After a repair install I have found my language/ keyboard settings unstable, It seems that on time pressing such as the ampersand key (@) will produce @, other times ".
Here are the various settings in Region and Languages
Region abd Language Format set to UK English; Location to UK; Location tab to UK (default).
Keyboard is set to UK in box and set as first in list below it.
On the Admin tab Input and Format set to UK; Welcome Screen input to US Format to UK; New User Accounts as Welcome Screen
Under the keyboard language options, is there another language installed?
If yes - check if you maybe press Alt + Shift at times (which is the default hotkey for changing the input language).
How to solve? Unless you use that second language, try setting your used language (the one you want) to standard and delete the other one.
My Computer
OS
Windows 7 Ultimate x64
CPU
Intel Core i7-2600K
Motherboard
ASUS P8P67
Memory
16 GB (4x4) G.Skill Ripjaws DDR3-1600
Graphics Card(s)
2048MB HIS Radeon 6970 IceQ Turbo
Sound Card
Creative X-Fi Xtreme Audio
Monitor(s) Displays
Iiyama ProLite B2712HDS (27"@1920x1080)
Screen Resolution
1920x1080
Hard Drives
2 TB on usual HDD
60 GB on OCZ Vertex 3 (SATA3) for Windows
240 GB on OCZ Vertex 3 Max IOPS (SATA3) for games
as above, First thing I alway's do after fresh install. Set 1 language/keyboard and delete others.
If you use only 1 language.
You'll find language setting in configuration panel. (search for change keyboards or other input methods). Press Change keyboards.
Make sure you have only 1 language and 1 keyboard setup. Than you cannot change it accidentally by pressing the alt shift change language hotkey.
(and when you're at it, also make your language bar invisible (Tab language bar).)