File Extension USG File Format PC- Doctor for Windows file USG stands for PC- Doctor for Windows file. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question Reading, Deleting, Writing Rows to Oracle Data Base OPENING DOCX FILES THROUGH IE 6 indexes status error Chkdsk won't run on (SCSI) Disk 0 with FAT and NTFS Need advice.