I don't check these forums daily but when I do, this is one of the sections I do check as I have quite a lot of knowledge about computers and basic programming skills in a few computer and web-development languages. The problem with helping people online with their computer problems is enough detail has to be given, ideally a description of what's going on, screen-shots and any error messages (if there are any). Also, if your computer problems happened shortly after downloading something, please give the name of the file (i.e. name.exe). Preferably, don't give the URL in case someone opens it and gets the same problem! The only time I would open it is if I use my other computer and open it in Sandbox. Sometimes you'll be asked to download and run certain programs that can generate log files, which can give further information about your computer and hopefully sort out the problem.

One piece of advice I've often seen given is to clean out the registry. I recommend to NOT do this as it can result in other problems, even if it does fix the current problem.