internet security woes

Last week, my computer stopped saving passwords, and began making me log in for everything important. This is obviously the most safe option, but I find it really annoying. However, the most frustrating thing I've found is this: I can open blogger without logging in, however, I can't post comments on anyone else's blog. I'm not sure what the heck is going on, so if anyone reading this can help out....please let me know!