How to change Page file size on Windows Server 2012?
Basically page file should be 1.5 times the RAM available on server however, it may vary if you have Virtual Machine practically it's not always feasible to set huge amount of page file on server as it requires very large disk space.
You must be logged on as an administrator or a member of the Administrators group in order to complete this procedure. If your computer is connected to a network, network policy settings may also prevent you from completing this procedure.
1. Open System in Control Panel.
2. On the Advanced tab, under Performance, click Settings.
3. On the Advanced tab, under Virtual memory, click Change.
4. Clear the Automatically manage paging file size for all drives check box.
5. Under Drive [Volume Label], click the drive that contains the paging file you want to change.
6. Under Paging file size for selected drive, click Custom size, and type a new paging file size in megabytes in the Initial size (MB) or Maximum size (MB) box, and then click Set.
If you decrease the size of either the initial or maximum page file settings, you must restart your computer to see the effects of those changes. Increases typically do not require a restart.
a. To have Windows choose the best paging file size, click System managed size.
b. For best performance, do not set the initial size to less than the minimum recommended size under Total paging file size for all drives. The recommended size is equivalent to 1.5 times the amount of RAM on your system. Usually, you should leave the paging file at its recommended size, although you might increase its size if you routinely use programs that require a lot of memory.
c. To delete a paging file, set both initial size and maximum size to zero, or click No paging file. Microsoft strongly recommends that you do not disable or delete the paging file.