what is slowing me down to a crawl?

I am in need of really emergency help.  All of a sudden, every action I take in X7, causes my hard drive lite to come on. Going from one tab to another, the lite come on. I am running an I7, 16 Gbytes, medium video card and using 64 bit X7. Any thing I do, edit text, move text, move graphic takes for ever. A job I am working on that should take a couple of hours is taking a couple of days.  I even reduced my display to "Draft", cancelled backups, I am saving by creating new files. No templates being used and in fact this is a file that was created last year (x7) and being update this year. I have scoured the forums, looking for anything -   I must finish this job in a day or two.... that seems impossible at the current rate of work I am able to get done. I am working with two files both about 160 megabytes. Here is something that is the real puzzler,  with just the welcome screen open, the same thing is occurring????????