Google Picasa Web Albums is online photo and video storage which offers 1 GB of free storage. With the introduction of Google+ Picasa is now offering unlimited photo hosting for all of its users. There are several condition to get unlimited storage. It's different between normally Google users or Google+ users.
Here the condition according to Google Picasa Help
If you have installed Google Software (Chrome web browser, Google Desktop, or Picasa), you might have noticed about a new process "GoogleUpdate.exe" runs in background. Even if you end task of this process using Task Manager or third party program, it automatically comes back after a few minutes or when you launch Chrome web browser, Google Desktop, or Picasa next time.
Google has been added new feature on homepage. Now you can change white background with another image. This new feature is very funny and maybe useful for some people who don't like simple and clean interface. But to active this feature you must login first to your Google Account.