If you go to the Tools-->Options-->Security tab, there is a selection for allowing access to potentially unsafe attachments. If you know who is sending you stuff, you can uncheck this box, otherwise OE blocks access to ALL attachments.
Spec:
Intel P4 2.4B
MSI 645E Max-U Mobo
1GB DDR333
R9600XT 128MB
SB Live 5.1
WD 60GB
Maxtor 120GB
LG DVD+-R/RW
WIN2K PRO SP4