Here is a collection of the USMLE Pretest series which includes:
Biochemistry.pdf
Chest Radiology.pdf
Emergency Medicine.pdf
Medicine.pdf
Microbiology.pdf
Neurology .pdf
Neuroscience .pdf
Obstetrics and Gynecology.pdf
Pathology.pdf
Pathophysiology.pdf
Pediatrics.pdf
Pharmacology.pdf
Physical Dignosis.pdf
Pretest Clinical Vignettes.pdf
Preventive Medicine.pdf
Psychiatry.pdf
Surgery.pdf
Thanks to \"murichandi_y\" who put it up first. I have re uploaded to MiHD because they are hassle free. However files are deleted after 60 days of inactivity so make sure you pass the link on!