You do not HAVE to have a pagefile operating for Windows to work, although it is HIGHLY recommended. I suggest you get rid of it temporarily for the re-sizing job, then re-create it.
The Pagefile is also known a Virtual Memory. To get at it, go to Start ... Control Panel ... System ... and choose the Advanced tab. In the top Performance block click on Settings. Then choose the Advanced tab and at the bottom Virtual Memory block click on Change. There are three choices available. The first, Custom Size, allows you to set your own parameters. If that is already chosen, note down the two settings so you can re-create them later. If it is set to System Managed Size, just note that. Then choose No Paging File. It will warn you of dire consequences and ask you to confirm this silly choice. Confirm. You will have to back out and reboot your computer to put this choice into use. But now there will be no Paging File on any drive, and you can make your changes.
When you're done, go back through the same route and re-establish the original setting, back out, and reboot again.
Now, I have two notes about resizing your C: drive. One is that windows won't do that, but I see you plan to use Diskpart.exe. I really don't know whether that tool included with your OS will do it - Microsoft tries to prevent users from doing dangerous things like this. However, there are third party utilities to do this, like Partition Magic, and a few free shareware tools.
What MIGHT be a bigger problem is that you normally can expand a Partition by adding to it only CONTIGUOUS Unallocated Space. That is, the extra space you want to add MUST be empty and right at the end of the existing C: Partition. My guess is that your hard drive was not Partitioned this way, since you have two other Partitions active. There are ways to do this like making a complete backup of each Partition, then deleting all the Partitions except C:, expanding it, then re-creating the old Partitions and restoring their data. Alternatively, some of those third party utilities may well be able to do all of that for you. Just be sure to read up on their ability to do the job you have in mind before you buy or run them.