Q: Deleting pop-ups on my desktop?

Download and run MalwareBytes. Malwarebytes was developed by one of our own colleagues here in ASC. It's is used by Apple Geniuses at Apple Store Genius Bars. It is also recommended by Apple Community Hosts here in the forums, as well as by Apple Telephone Support agents.

Fixes for Adware and Pop-up

  1.

1. Malwarebytes
2. DetectX 2.11
3. Remove adware that displays pop-up ads and graphics on your Mac
   
4. Stop pop-up ads and adware in Safari - Apple Support
   

Please ignore remarks such as “Don't use any kind of "anti-virus" or "anti-malware" product on a Mac.“ Such remonstrations are an exaggeration. They may be needed in some situations, but need not be installed or used for all circumstances. Furthermore, adware removal programs make the job of removal much easier. They require no permanent installation to remove adware or other types of malware. They do no damage, and they don’t make you more vulnerable to attack.

If you need more space on your SSD:

How to Free Up Space on The Disk Drive

1. You can remove data from your Home folder except for the /Home/Library/ folder.
2. Visit The XLab FAQs and read the FAQ on freeing up space on your hard drive.
3. Also see Freeing space on your Mac OS X startup disk.
4. See Where did my Disk Space go?.
5. Be sure to Empty the Trash to recover the space.
6. Replace the drive with a larger one. Check out OWC for drives, tutorials, and toolkits.
7. Use OmniDiskSweeper 1.8 or GrandPerspective to search your drive for large files and where they are located.