Thank you all for the replies, and I realize that I've been flooding the forum with updates about the situation constantly, and that could tend to get annoying- sorry about that. Right now, Dp 5 and 6 are working fine on my system, so that's all that I really need by now, and I'll be trying to figure out what is wrong with 7 sometime in the future- need a break from this constant error-searching!

I've been working with DP for 5 years and never thought that the "new file" option is a waste of time, if you put your templates in the template folder and then click on "new-> template you want to use", isn't it just as good as opening a project file?
So again, thank you so much for your help/moral support/suggestions etc

And if anyone besides legodo and me experiences this strange thing, let me know.