Nortan 2011 Messing up User Profiles and sending laptop to sleep constantly

Hi, I recently installed Nortan 2011 onto my machine. I previously was running nortan 360 without any problems until my subscription ran out. After the installation of Nortan 2011 i restarted my laptop and then the trouble begun! I logged into my user profile as usual and it took me to a "guest profile" instead of actual main admin profile. Strange indeed, further still every 30 mins my laptop goes to sleep ( without any warning before hand and with no error messages) I'm at odds what to do, i may have to roll back my machine to a previous date prior to norton being installed and download free anti virus software.

 

<b> Laptop spec:</b>

 DELL Studio XSP 1645

 i7 intel core

64 bit

 I had no problem prior to the installation this is why i suspect Nortan to be the offender!I have no other anti virus software on my machine apart from nortan. I hope somebody can help!Let me know if you need any more info. Many thanks Amelia