<rant>Once again Krapoo customer service is abysmal at best.</rant>
Right then, sounds like you have some sort of virus/trojan/root kit on your system. Do you have any anti virus? Do you have a software firewall? if the answer to either of those questions is no grab a copy of this
http://files.avast.com/iavs4pro/setupeng.exe and or this
http://www.sunbeltsoftware.com/Home-Home-Office/Sunbelt-Personal-Firewall/.
Right now it's time to root out what is sending all that spam mail, grab this
http://www.trendsecure.com/portal/en-US/_download/HiJackThis.zip this
http://download.sysinternals.com/Files/ProcessExplorer.zip and this
http://download.sysinternals.com/Files/TcpView.zip.
Hijackthis will produce a log file of all the services running and programs that run during boot up, feel free to post the log file if you'd like someone to offer some further help.
Process Explorer will display a real time list of all processes running at any time, think of it as task manager on steroids. Try and look for processes using way too much CPU.
TCPview will display in real time all the network connections each program is making, you are looking for services/programs which are making connections to other hosts on ports TCP 25,110,143,465,585,993,995, mainly it will be port 25.
Once you have located the process sending mail then use hijackthis log file to find out how it's getting run in the boot up sequence. Then you should be able to remove that entry and stop the malware from being reloaded onto your computer when you next reboot.
I would probably google the file names of the malicious program and try and find out which virus/trojan was causing all these problems, then try and find a removal guide.
Get your important data backed up right away and if the above fails or sounds like too much work just re-install your OS.
