txt files

Many txt files will be OK to delete, but some certainly would not. Many applications use data stored in text files for configuration settings and other things. I wouldn't go and delete everything with a txt extension. You're asking for trouble. Take it on a file by file basis. If you're trying to clear disk space, look at the largest files first.

Not all those txt files will cause a problems to your computer provided you know which one will and which one wouldn't. If you are using XP you shouldn't be worry fr that cause you can always create your restore point and you an roll back to the good one before changes should accidently delete any files or program wrongly.