Aspire S3 paging file using 100% disk usage after upgrade to windows 10

After about two weeks of blazing-fast Windows 10, it started hanging. The mouse would start stuttering, the keyboard would output after a minute, and my entire system was very slow. In Task Manager, the disk usage on my C:\ drive was displaying as 100%, and in Resource Manager, C:\pagefile.sys was at the top of Disk (I/O).

Booting into the Safe Modes is quick, and it doesn't hang in there. I have tried system restore, but all of my restore points give the error message "Windows could not extract <filename> from the restore point." The error code was 0x80070017 for all of them. What should I do?