Hi Running a Dual Opteron 242 Windows 2003 Standard with Plesk for windows installed. Occasionally some sites (not all) will suddenly stop working. What happens is when i launch the site in my browser it will ask for a username and passwords??? Its very weird. This just happens out of the blue. One time this happened to a site and to fix it I had to reupload all the files again. The latest time this happened, to fix it, I had to delete the domain in Plesk and re-add it and upload the files again. Its nothing to do with the network...there are obvious problems between Plesk and the Windows OS. I know Windows has IIS on it...and plesk uses Apache to run?? ...so could be some stuff going on b/w the two. Or could it be some DNS stuff..? The particular site was recently moved over from another server. Keep in mind that some other domains seem to be working fine and never have had this problem. Its just certain other domains. Anyone have an answer to this problem? This is very scary considering that I do not know what triggered the site to stop working.....it just happens suddenly and to fix it i have to use one of the two methods described above. Thanks in advance. PS. Oh and SITE PREVIEW is not working too now but the domains are working again after performing the "fix" above.