Compaq Presario desktop computer Review

I purchased this computer about 2 years ago. Within 2 months of purchase, it had a major malfunction and was sent into manufacturer. Received it back a month later. It ran ok for awhile then began having small issues such as poor graphics, running slow, etc. Now the computer will not even load. Everytime you shut it down and boot it back up, it needs to go through the repair. Sometimes it will complete it, other times it will not. It just goes to a black screen with a flashing cursor and does nothing. This is a real problem for me because my child uses it for school work and I am supposed to be completing a online college class. I feel that the main problem with this computer is the OS. It runs Vista. I have not been impressed with the OS from the beginning. I have talked with a lot of computer experts over the issues that my computer is having and all seem to say the same thing, "We have had a lot of people with similar issues and they are all running Vista as well." They reccomend upgrading to Windows 7, but my problem wth that is if I am going to spend $199 for a program, I may as well put a little more with it and purchase a totally different system just in case it is not only Vista causing problems.