Firefox Sync can transfer bookmarks after you sign in to the same Mozilla account on both PCs, but a local HTML export gives you a file you can inspect and keep. Do not confuse bookmarks with passwords, open tabs, or extension settings: exporting bookmarks to HTML transfers bookmarks only. Use Firefox's separate password export/import or account Sync if those items are needed, and protect any password export as sensitive data.
Step 1. In Firefox open the menu, choose Bookmarks > Manage bookmarks, then select Import and Backup > Export Bookmarks to HTML.
Step 2. Save the file as bookmarks.html in a folder you can find. Copy it to an external drive or trusted network folder. Do not erase the old profile yet.
Step 3. On the new PC, install Firefox from Mozilla, open Manage bookmarks > Import and Backup > Import Bookmarks from HTML, select the exported file, and check several folders and URLs. Import may add to existing bookmarks, so review duplicates before deleting anything.
Firefox's own bookmark backup format preserves its bookmark structure for Firefox restore, while HTML is better for transferring to other browsers. A full profile copy also contains history, extensions, and potentially sensitive account data, and should be attempted only with Firefox closed and with a version-compatible profile. For a simple bookmark move, the HTML export is safer and easier to verify.
This creates a separate file-backup task; it does not change the originals. Connect a healthy external drive before starting.
Step 1. Open Backup and Recovery > File Backup in Qiling Disk Master.

Step 2. In the source tree, select the folder containing bookmarks.html and any other personal files you want to move. Check each selected folder rather than assuming everything under the user profile is included.

Step 3. Choose the external drive or a separate network location as the destination. Compare its letter and available space with the source; do not save the only backup on the source disk.

Step 4. Review the task, click Proceed, and wait for completion. Browse the resulting backup and restore a test file to a different folder before relying on it.

Export, import, and verify bookmarks before retiring the old computer. Keep a separate copy of the HTML file until the new browser is confirmed.