I found out what the problem was. I had added a program to my computer called PrivDog, which is supposed to protect me from viruses, pop-ups etc - but it kind of went too far! It took away BlogSpot's menu, which allows me to sign in and write my daily entry.
Programs like PrivDog are, to me, like over-protective parents. So, figuratively speaking, I had to tell my dear old parents that BlogSpot and other websites are really good kids and that I should be allowed to hang out with them.
Sheesh! I hate being over-protected!