If you find the visual studio takes a long time opening up solution, you can try one of the following methods:
Method 1: Open sln from vs:
Steps:
1. Kill visual studio in task manager.
2. Start visual studio as a standalone application (ie: not from the .sln file).
3. Then, open the solution from within visual studio.
This solution is the safest because there is not need to change any settings or delete any files.
Method 2: delete the .suo file:
Inspect the devenv.exe process with Process Monitor.
If you find that it is pretty busy with accessing the .svn directory, then try:
Steps:
1. Kill Visual Studio.
2. Delete the solution's *.suo file.
This is located in the same folder as the solution itself.
Note: You will lose several settings for your solution, like currently opened files, breakpoints, bookmarks, current solution configuration and platform (eg: Debug x86) etc.
3. Restart Visual Studio
4. Load the solution
For more information, see here.
