I have downloaded hijack this but it wont let me make a log because my adobe acrobat wont read a file that doesnt start with %pdf. Im not sure what to do. Ive tried renaming the file. Still gives me the same response. ???

Pentium 4 1.4 gig
Windows Me
Mozilla Thunderbird
Mozilla Firefox
Sygate Firewall
Avast 4.6 free home edition