I have the same problem, on Win7 and portable distribution of uWamp.
uWamp was worked previously,
1- i was copy the folder on a "backup"
2- reinstalled Win7 ( with some windows updates ), and redist vc11
3- now uWamp - apache won´t work, no messages, no logs just crash
SOLUTION!!!!
I have resolved my problem by installing vc11 x86 from here
https://www.microsoft.com/es-ES/download/details.aspx?id=30679
How to found...
By executing uWamp/bin/apache/apache.exe a message apears that tell MSVCR110.dll is not found.
And http://answers.microsoft.com/en-us/windows/forum/windows_8-winapps/the-program-cant-start-because-msvcr110dll-is/f052d325-3af9-4ae5-990b-b080799724db?auth=1 >> Yaqub K answers tell about solution.
Thats all folks!!!
sorry about my english... ;)