Very slow (despite High Speed Internet service and PC Power Boost).

Check your computer high speed here:

http://www.speakeasy.net/speedtest/

You can determine after check your speed if the problem comes from your provider or from your computer.

If come from your computer there are many reasons that can be causing the low performance
mostly related to a hardware issues or virus/spyware issues

Try removing unnecessary programs that leads to poor pc perfomance.if nothing helps reload the operating system completely and install only the programs which r needed.the speed will automatically get improved.

Sometimes  the enabled  ---javas and the active x controls ---makes the pc perfomance slow. just check that out and make them disabled.

Is your pc runing slowly? The easyest solution would be to use the recovery cd to restore the computer to the original sate OR, remove useless files from the system with ccleaner www.ccleaner.com  after that is complete remove any useless extra programs from start -> control panel -> add or remove programs. 
ones that is done follow this page http://www.microsoft.com/AtWork/getstarted/speed.mspx

that should help. If you need help, I could do this for you over remote support? if intrested. Add a comment, note that reposting on my problem will reject my support.