The presence of immovable system files, especially a swap file, can impede defragmentation.

So with something like that, where they've made a point of protecting the swap file, you're safe.

The swap file is a portion of the hard drive where Windows temporarily stores information when much faster random access memory is full.

The only memory evidently added was in a larger swap file.

This virtual memory storage area on the hard drive is often called the page file, or sometimes the swap file.

Because of the additional memory I've decided not to use a permanent swap file.

The rest exists on disk in some form, usually in one or more "swap files."

No matter how much RAM you have, you will almost certainly hit the swap file eventually.

Simply moving the swap file to dedicated partition on the same disk is of much smaller benefit (if any).

This results in more memory being available to run applications, and lesser usage of the swap file.