I used Geany 0.18.1.1 under Win7 to view .txt and .xml-files. Works great! (We learned Geany to know from our pc's running Linux)
I removed the old version and installed the newer version Geany 0.2. After installation Geany does not appear anylonger in the list of programs to open a .txt-file, .xml_file, aso. I wiped the new version and tried to install the program as an administrator. Although the new version works fine, you can't set it as a default-program. To "solve" this issue I reinstalled the older version again.