How do I use internet comments in my research? I want to use comments on the internet to gather user requirements.

I plan to collect these comments, read them and decide what the person wants based on what they've written. These list of "wants" will form the user requirements.

For example:


  John: I hate the way the program keeps asking me if I'm  sure I want to exit.


Could form the requirement:

An option to disable exit confirmation prompts.


What's a suitable methodology for this? I need a process to follow or guidelines to do it correctly. Is it classed as qualitative research?
You would generally need to use a class of research that is indeed considered qualitative. I think the most common method would be "coding", and if you search for "qualitative coding" you should find a wide-variety of helpful primers such as this one. 

A more detailed guideline on how to do this type of research would not be on-topic here, but with the right search terms you should be able to find a wealth of guides from a variety of different fields. However, no resource you find will be an adequate replacement for getting to know your own field and how  things are done there by carefully reading the method sections of papers in your area that ideally use similar methodology. If you draw up a provisional plan for what to do (creating your own sample data to go with it can be helpful here), you should have it reviewed by a suitable advisor/researcher in your area to help you understand how things are generally done in your area, and to help you identify problems and misunderstandings in your plans.