I have been using Mozilla Firefox 1.0 browser on my previous computer for a few months and it has been really great. When my computer broke down at the beginning of December 2004 my gracious daughter got me a new one. Since then the Firefox browser fails to load images on certain sites I go to to find icons, celebrity, comic book and album covers and sports photos and the like. On some sites the thumbnails appear but when I click to enlarge nothing happens. On other sites nothing appears, as the boxes show no thumbnails nor anything else - it just comes up with blank boxes. When I use Internet Explorer some sites don't load but on other sites thumbnails load and images enlarge normally, while with Firefox the thumbnails won't enlarge. I don't recall changing any preferences on either browsers. Trying to help myself I was able to restore the defaults in Internet Explorer but couldn't find in the Help section how to restore defaults in Firefox. On my old computer on the same sites everything worked perfectly, thumbnails all loaded and when clicked enlarged with no problems. The main differences between my old and new computers are as follows:

Previous computer: Intel Pentium lll 800MHz, 256MB SDRAM Hard Drive:30GB, Windows XP Professional without SP2, Nortons SystemWorks, Zone Alarm, Mozilla Firefox1.0, Internet Explorer 6.0. New computer: Intel Pentium 4 Processor 540 with HT Technology 3.20GHz,Microsoft indows XP Home Edition with SP2 pre-loaded, 1GB DDR2 SDRAM, 160GB SATA Hard Drive, pre-installed with Norton Internet Security. Identical browsers Mozilla Firefox1.0, Internet Explorer 6.0. I don't believe this makes a difference but I mention it anyway. I installed Nero 6.6.0 Ultra Edition: CD/DVD Burning Suite and somehow my default image viewer is now Nero Photosnap Image Viewer. I much prefer to use Windows Image & Fax Viewer, so if anyone can answer the secondary question on how to make Windows my default viewer I would be most pleased. I am a senior pensioner with not very good computer skills, so please excuse if my question is more detailed than necessary. Also I did my best to search the threads but couldn't locate the problem I have with images not loading and/or not enlarging. I am truly grateful to have a resource like Tek-Tips to turn to for help and take the opportunity to thank the great folks here for helping me in the past. Thanks and take care everybody.