x86_32+SSE2
or x86_64
CPU architectureAt the time of writing, there is no version of Safe Backup Plus available for Windows XP / Server 2003. All versions of Safe Backup Plus rely heavily on features that were only introduced in Windows Vista / Server 2008.
Windows XP / Server 2003 no longer receives security patches from Microsoft. It is unsafe to connect such a machine to the internet. If you are attempting to supply backup services to a customer in this situation, you should arrange to first upgrade their operating system with urgency.
You can work around this issue by