I fixed it but not with the solutions I was reading about. Probably someone has already explained this but maybe this will help someone else with Windows 7, MS Office 2010 and Word double-space issue:
In plainspeak from one who does not utter a word of computerese:
Go to upper right of screen to 'Change Styles' (next to 'aA')
Then choose 'Paragraph Spacing' in the drop-down box
Next, under 'Built In', choose 'No Paragraph Space'.
Choose as default for all documents.
Who knew? I was looking for 'line spacing', and nothing worked, until I decided to try as a last resort - before grabbing pen and paper for an excruciating round of handwriting the many documents I need to work on - 'Paragraph spacing'.
Whew.