I was working with an old version of Tikz. It appeared I could not use some features, probably because I had an outdated version.
So I tried to reinstall a new version of pgf. I downloaded it and tried as best as possible to get it installed... No result. The instructions are a shame. Even worse: in the process of doing so my old tikz does not even work anymore. It says 'I can't find file pgfutil-common.tex'.
I probably did something wrong.
Can somebody please tell me - in detail and in extremely simple terms - what to do? Even if I now run '\usepackage{Tikz}' it doesn't work.
I have a TexShop. In some map in my library I have a map called 'Tex'. I think I did something wrong by changing things in this map.
Sorry for my incomplete information.
I'm working on a Mac operating system.
In the map 'TeX' where I believe my tex is installed there is a file called 'TeX Distribution Helper', if I click on it it says 'Choose a system wide TeX distribution'; then I have two options, either gwTeX or TeXLive-2007. So far I've always been using the TeXLive-2007 option I believe - until yesterday, for some reason I changed it to gwTeX. I think I perhaps screwed up by changing this to gwTeX (from that moment I think the Tikz package didn't work anymore).
I've now re-set this to 'TeXLive-2007', and the Tikz works again - that is, if I put \usepackage{tikz} in my tex-file I do not get error messages, and I can use the "basic" commands in TikZ, they work and without errors. However, I still cannot use most of the TikZ libraries and so on (for instance, if I put \usetikzlibrary{shadows}, I get the message 'I can't find the file pgflibrarytikzshadows.code.tex'). Remarkably, \usetikzlibrary{arrows} does work.