45kbps is not enough to mine on.
neither is a 145 sempron. if i was you i'd go with a online wallet service. you can buy BTC from mtgox.com
Ok, I can upgrade these 2 things. But first I need te see that they will really work. Please tell me what to do?
You might want to visit this thread
https://bitcointalk.org/index.php?board=14.0. I notice you're a newbie so be aware that you won't be able to post until you've graduated. However, you're still able to watch threads so skim through them and you might find the answers you're looking for. Once you've graduated you can easily go back to helpful threads that you've marked to watch.