Adobe Reader does not open .pdf

A client is running Windows ME with Ram 256, and has 13 gig
unused hard disk space. He tries to view a Adobe .pdf file from a
internet site. His ISP is AOL. His IE is 6.0

When he clicks on the link to open the .pdf, it begins the
download, Adobe Reader Opens, but then he gets a white screen
and nothing happens.

He has set the secutity to low in Internet Options.

Any ideas