Thank you Lorien for your thorough analysis of what I need to do to solve my dilemma. Word now seems to be working without "not responding" errors, and I can use it for its main purpose, which is word processing. As I explore the new features, I see that Microsoft has incorporated a lot of picture-enhancing tools, somewhat like including PhotoShop into the software. As a photographer, I would never use these tools because I have been photo editing in PhotoShop since Adobe's very first version. Also, I do most of my page designing and layout in Quark Xpress. I just want a good word processor to take care of my business functions, i.e. letters, writing stories I can import into Quark, and mailings. Mail merge is important to me, but if I have to export a data file to another software to do it, so be it.
At this point, I guess I'll just bite the bullet and do my mail merging elsewhere. Yes, it may be an Outlook problem. Maybe I made a mistake when I created another Contacts folder for my Christmas list, copying from my address book the names I wanted to send cards. I did that before in Outlook 2007 with no problem. Word will not recognize this folder, giving an error message that it cannot find the object. So, I had to use the regular contacts folder, uncheck all names and then recheck the ones I wanted to send cards to. But I could never complete the merge.
As for memory, when I check the Resource Monitor, it says I have 4096 MB installed, with 9MB in Hardware Reserved, 1300 MB In Use, 53MB in Modified, 2724 MB in Standby and 3-6 MB in Free.
I have no idea what all that means. In Physical Memory, it says 1300 MB In Use and 2700 MB Available. I don't know that that means either. Since uninstalling and reinstalling, I haven't had any memory error messages.
Thanks again for all your help.