Hello
I believe you are doing wrong questions, How much memory server has? How much bigger page file is?
I'm pretty sure that it is not enough big because error is coming from Windows not from DP, obviously if you select just one drive instead whole server workload is minor and backup works.
Check link below for to determine if your page file size is right.
https://support.microsoft.com/en-us/kb/2860880
Best Regards