Why does F10 (step over) in Visual Studio 2010 not work?
CamStudio application was the issue in my case.
Somehow it reserved this key to itself and Visual Studio was not able to use it anymore (I've tested it MS Word (Alt+F10 - was working as expected, while CamStudio was on - when minimized it appears only in SysTray)).
I've closed CamStudio and it was fine:
F10 functionality "reappeared" in VS2008.
In the Options.Keyboard page, please select "Debug.StepOver" from the command listbox, and then put focus to the "Press shortcut keys" textbox and press F10, click Assign button to re-assign shortcut, does it work?
You can also try to run Visual Studio under safe mode, which will prevents all third-party VSPackages from loading when Visual Studio starts; if the issue disappear under safe mode, you may consider checking your installed add-ons or VSPackages.
Second, to log all activity of Visual Studio to a log file for further troubleshooting, please use the /Log switch, and post the log file content here, so we can do more investigation on it.
If this feature works well before, and suddenly behave abnormally, it usually indicate that some files or configurations of Visual Studio installation is corrupted or missed, you can:
Restores Visual Studio default settings by using "Devenv.exe /ResetSettings" command. Please backup your settings before restore to default settings.
Repair/reinstall Visual Studio;
To repair Visual Studio In the Add or Remove Programs dialog box, select Visual Studio then click Change/Remove.
Turns out my issue was simpler/more embarassing, but I figured I'd post it just in case it helps someone else.
I had the F Lock (function key lock) turned off, so my F10 keypress wasn't being sent as such. With these newer keyboards (mine is an MS wireless keyboard), there are several modifier keys that affect the keyboard behavior.
Once I enabled F Lock, everything worked as expected.