Problem with multiple software

My notebook operates with Vista Home basic edition and recently had to deal with some unpleasent malfunctions in several programms I use. Open Office org and Paint.net have the same problem - save as window is gone,when I choose save as in file, nothing happens. Cant create a new document!! Has anyone any ideas about this? Along with this,the desktop shortcut in startup in no longer functioning. Tried to write the explorer command in notepad,it did not work.
I would be very thankful for any info about this! :censored2