File Share Encryption

My question is about when is my hard drive encrypted.  Is the full drive de-crypted after logging in, or only as it accesses files?  Here is my specific question and situation...

I run Symantec Endpoint Encryption (PGP) for my laptop... not server hoted, but residing direclty on my laptop.  I ran the full disk encryption to encrypt my hard drive.  When I log into my computer I enter via the Symantec log-in screen, and then after that the Windows desktop log-in screen.  I'm wondering at this point is my hard drive fully decrypted?  After screen saver mode I log back in on the Windows screen, but NOT the Symantec screen.  Does this means my drive was decrypted after the Symantec log-in and no longer protected?  If my computer is stolen in screen saver mode, could someone access my files?

Thanks in advance for a reply.

When you authenticate with bootguard, that the moment where the files allowed access essentially.  If, for arguments sake, someone stole your laptop whilst you were working on it in a coffee shop, they can copy the data off.  If it's off, or hibernating, they will have to know your password in order to access any data.

If it's a normal windows screensaver, the files are still open for accecss.  If you want to be sure, hibernate the machine or turn it off.