Free Antivirus Update

Hello Telemaco,
We apologize for the inconvenience caused.
Could you please let us know whether your system runs in Window XP Service pack 1 or Service Pack 2 or Service Pack 3. You can check this by pressing Window Key + Pause Break on your keyboard or hold Ctrl + Shift + Esc key the information will be displayed.
Please feel free to contact us for any further assistance. Thank you.

My OS is Windows XP Professional 64 Bit
My registred AVG protections are:
1) AVG Free Antivirus
2) Licensed AVG TuneUp expiring 16 May 2017
The Update Antivirus Free result forbidden because .... " the Operative System is not supported ...."!
How can I solve that problem?
Thanks
TelemacoI
Hello Telemaco,
We apologize for the inconvenience caused.
Could you please let us know whether your system runs in Window XP Service pack 1 or Service Pack 2 or Service Pack 3. You can check this by pressing Window Key + Pause Break on your keyboard or hold Ctrl + Shift + Esc key the information will be displayed.
Please feel free to contact us for any further assistance. Thank you.

Many thanks for your prompt answer. Please find here you requested data concerning OS and PC
System: Microsoft Windows XP Professional x64 Edition Version 2003 Service Pack 2
Registred to Telemaco Tomassetti Serial :  76588-652-8284616-50987
Computer : Intel (R) Xeon (R) CPU
W 3503 @ 2.40 GHz
2.40 GHz 7,98 GB RAM
Thank you