When Windows slows down, reinstalling often seems like the safest option. It promises a fresh start, one that will run like it did on day one. Often, performance issues stem from cluttered storage, not a faulty operating system. Every day, activities create huge photo libraries, project folders, sync services, and application data. When all of this data resides on the same drive as Windows, it puts extra strain on that drive.
How to fix with symlink
The system sees the path, not the folder
Instead of reinstalling Windows, you can move your heaviest folders to another drive and leave your system where it is. Symbolic links, also known as symlinks, allow Windows to continue using the original path while the data remains on another drive.
Moving folders to another drive sounds simple in theory, but problems start to arise when programs can't find them. Most apps rely on fixed file paths, and when those paths change, the software considers the data lost. Game launchers start asking to reinstall, editing software opens empty projects, and media apps lose track of their libraries.
Windows has a built-in solution to this problem: Symlinks. This makes a folder appear in its original location, even though the files are now on a different drive. When a program opens that folder, Windows redirects it to the new location without showing any difference in Explorer. From the application's perspective, nothing has changed. The path looks the same, so the program treats it as the original folder.
This is also the difference between a symlink and a shortcut. A shortcut is just a pointer that takes you to another location. A symlink lives in the file system. Windows treats it like a real folder. When an application opens a folder through a symlink, Windows automatically sends a request to the real location. In most cases, the program never sees the new path. It continues to behave as if the folder had never been moved.
It's this behavior that makes symlinks so useful in this situation. Entire folders can be moved to another drive while all programs continue to use them as before. The system drive stops filling up; the data is on another drive, and Windows continues to function normally.
Set up secure mklink
Redirect folders properly
Once you know what a symlink does, setting one up is essentially a matter of running a single command. Windows has a built-in tool for this called mklink , which you can use from the Command Prompt . You can point it to an entire folder or a single file, depending on what you want to move.
First, move the folder to the drive where you actually want the data. For example, if the folder named Projects is on drive C, move it to drive D. After moving, C:Projects will be empty. Delete that empty folder so the symlink can reuse the same path. Then, open a Command Prompt with admin rights and run the following command:
mklink /D "đường dẫn thư mục cũ" "đường dẫn thư mục mới"
The first path is the original location where programs used to look for the folder. The second path is the new location where the files are now located. For example, you could run:
mklink /D "C:Projects" "D:Projects"After you run the command, Windows creates a special folder at C:Projects. When you open this folder in File Explorer, you'll see the files you moved, but they're still stored at D:Projects. Edit the document, rename a subfolder, or save new content, and your changes will be written directly to the folder on drive D. If you remove the link at C:Projects , the data on D will remain in its original location.
You can do the same with individual files. In that case, you omit the /D command and enter the exact file name.
mklink "C:Notessummary.txt" "D:Archivesummary.txt"Here, C:Notessummary.txt looks like a normal file, but any changes are transferred to D:Archivesummary.txt on the drive. This is useful when a program insists on reading a file from a path, but you want to keep that file somewhere else. Symlinks themselves use almost no space. They don't copy your data. Instead, they act as a bridge between the old path and the new path, so all the actual space still comes from the new drive.
Deleting a symlink only deletes the link at the old path. The actual data remains on the new drive. When you delete a link, you only delete the pointer, not the actual destination file or folder. However, when you delete a file via a symlink, you delete the actual files in the destination folder, just as if you deleted them directly from their location on the new drive.