Computer slows down more each time I print a PDF. It reverts to a reasonable speed if I restart the computer. Everything worked normally until I installed Avast Virus Protection.

Question

I have Windows XP and Adobe Reader XI. My printer is a Ricoh Aficio 240W.
My computer normally lacks internet access. I briefly connected it to the internet to install the full version of Avast Antivirus, then disconnected it from the internet again, and it has been disconnected from the internet since.
After I installed Avast the computer began acting screwy when I printed PDF files. I uninstalled Avast but the screwiness continues.
The image in the upper left corner was taken after doing one printing of a PDF file. I'm pretty confident AcroRd32.exe. is Adobe Reader. Notice that after running one print Adobe Reader is using about 50 CPU's.
The image to the right of that was taken after doing two printings of a PDF file. Notice that after running two prints there are two AcroRd32.exe processes using 50 CPU's.
The image below the other two was taken after doing three or four printings of a PDF file. Notice that after three printings one AcroRd32.exe process is using 50 CPU's and two others are using about 25. After about three printings my computer slows down dramatically, and it keeps getting slower the more prints I do.
When I restart the computer it reverts back to normal. Can anyone think of a better solution to this problem of increasing slowness than restarting the computer every two PDF prints?
My computer currently has no virus protection, although Windows Firewall is up. Someone at Avast I briefly mentioned this too thinks this should not happen and he was wondering if the computer has some sort of virus...but before I removed Avast it told nothing about viruses that I know of. I honestly do not know if anyone scanned the computer with Avast before removing Avast, but I suspect it was scanned before the removal of Avast. I suppose this could be the result of some virus...but then the computer behaves quite normally, except when I print PDFs. I'm wondering if Avast changed some settings in my printer program or Adobe programs....
I have CCleaner. Every time I analyze my computer to look for stuff to remove to speed up the computer it shows Internet Explorer history files, and sometimes Internet Explorer temporary internet files despite not being online. If I click on Internet Explorer to go onto the internet, I am told I am working offline.
Thanks. Guesses are welcomed.

Answer 1

Note that regarding this section:
The image in the upper left corner was taken after doing one printing of a PDF file. I'm pretty confident AcroRd32.exe. is Adobe Reader. Notice that after running one print Adobe Reader is using about 50 CPU's.
The image to the right of that was taken after doing two printings of a PDF file. Notice that after running two prints there are two AcroRd32.exe processes using 50 CPU's.
The image below the other two was taken after doing three or four printings of a PDF file. Notice that after three printings one AcroRd32.exe process is using 50 CPU's and two others are using about 25. After about three printings my computer slows down dramatically, and it keeps getting slower the more prints I do.
The layout changed when I posted. Therefore, what I mean by the image in the upper left corner is the image at the top. What I mean by the image to the right of that is the image in the middle of the other two. What I mean by the image below the other two is, of course, the image at the bottom.