Irfanview would be my first suggestion, too. I'll send an e-mail.
PSPad is another invaluable freeware tool. Author is Jan Fiala, support AT pspad DOT com
Another one I'll send some words of thanks to, is "Jackass JoeJoe" of joejoesoft.com (ArsClip, StartRight, RenameMaster): jackass DOT joejoe AT gmail DOT com