My current firefox session is 86,000k which isn't good at all, but it still works fine.
Explorer.exe is at 28,000k.
The CPU Usage % is determined by what you are doing on the computer. For example, an antivirus scan may bring your usage up 70-100%. Even streaming videos on YouTube can make it hover around 40%.
Whether this is good or not is determined on your Processor and how much RAM you have.
564MHz, 320MB of RAM, XP Pro, Serv. Pack 2.
XP really needs at
least 512mb to run flawlessly but it is recommended you have at least 1GB of RAM so you can use numerous programs and application (like Firefox is taking up 80MB of RAM for me).
AS for the processor, there isn't really much we can do here if it's a Laptop but if it's a desktop computer, it
can be changed.
However, I personally would go for a new computer. (not trying to force it on you or anything
)
I myself have an old laptop sitting next to me with the same specs as your computer and XP on it.