Visual Studio debugging/loading very slow
Here is how I solved the "slow symbol loading" problem in Visual Studio 2012:
Go to Tools -> Options -> Debugging -> General
CHECK the checkmark next to "Enable Just My Code".
Go to Tools -> Options -> Debugging -> Symbols
Click on the "..." button and create/select a new folder somewhere on your local computer to store cached symbols. I named mine "Symbol caching" and put it in Documents -> Visual Studio 2012.
Click on "Load all symbols" and wait for the symbols to be downloaded from Microsoft's servers, which may take a while. Note that Load all symbols button is only available while debugging.
UNCHECK the checkmark next to "Microsoft Symbol Servers" to prevent Visual Studio from remotely querying the Microsoft servers.
Click "OK".
From now on, symbol loading should be much faster.
Note that if you make any changes/downloads to Microsoft assemblies, you may need to go back into the Symbols dialog box and "Load all symbols" again.
Turning off intelliTrace fixed this for me.
In Visual Studio, Tools -> Options -> IntelliTrace
Then, uncheck the checkbox for "Enable IntelliTrace".
None of this worked for me but I found a Breakpoint on a symbol that was deleted. Seems 2010 was hanging on it. To see if this is your issue do debug->windows->breakpoints If any are in there just delete them.
Saunders, mentioned he checked for that but it was not mentioned in the solutions for this problem. Maybe common knowledge for some, but not all of us.
I deleted the "Temporary ASP.NET Files" folder and my localhost page load improved dramatically. Here is the path... %temp%\Temporary ASP.NET Files\