Hello! after updating the wallet to version 0.7, no synchronization occurs! Help!
try deleting the blockchain and resync from 0, it could be you have passed the upgrade window and are now on the wrong fork, resyncing should resolve this (delete everything, except wallet.dat, wallet.dat is very important, to keep safe, and have multiple back ups)
Where is the blockchain on the computer?
read this thread, it tells you the location of the data directory based on your OS, including how to find it on Windows.
The blockchain is in the ./blocks/ and ./chainstate/ directories.