There really isn't enough information here to draw any conclusions.   You appear to have a 6 Gb virtual machine, with only 4 GB allocated to SQL Server, which for most business workloads, would likely be highly inadequate.   However, as you haven't said what kind of workload that SQL instance is supposed to be able to handle, we have no idea whether that quantity is inadequate or not.   Mind you, it would have to be really small to fit in just 4 Gb.    You also appear to be saying that Windows is suddenly using the paging file, and I have to guess that means that your workload is slowing down.   As you didn't provide any quantification of just how much slow down you're seeing, or exactly why the use of the paging file is a problem, I don't know what to suggest.   However, seeing that your last re-boot was 272 days ago, it would probably be a good idea to re-boot the machine anyway, and see if the problem remains.   If that fails to resolve the issue, then find out what changed in the application, or in the database, that might have started the slowdown.   Either way, if the problem continues, you'll need to provide a LOT more detail.