Unasked for addon

This is a follow up to my previous topic on removing avast free.Whist my avast was not working, and I booted Windows XP, and before showing normal XP screen, there was another screen with a horizontal leaved branch and a index line similar to XP normal screen. When the booting was completed, the screen appeared normal with all the icons.But they did not work as explained in my previous topic. On the screen appeared three circles, a large center circle, and on ether side a smaller circle. The were linked and with the mouse they could be moved off the screen. On the perimeter of each circle, there were small boxes. The boxes on the left hand circle were -log close,restart, off, The right hand circle boxes, dictionary etc. The centre large circle boxes- Words, control panel,etc. I did not add any programs previously to all this happening. It seems to me hat there was a two staged attack on my computer, first immobilising avast, and then introducing the addon. It probably was a genuine addon, but not for my version of XP.I am using FireFox, and I did not add any addon. Perhaps there is an explanation for this rather bizarre occurrence? I will very happy to receive any comments.

hey could it be that you have been attack by a rough malware? or it is it hardware related?

i suggest you do a scan with malwarebytes antimalware as a first step.

download install, update and do a scan.

remove what it finds and a system reboot might be needed

http://filehippo.com/download_malwarebytes_anti_malware/

do you have the name on the addon that was installed? could also be that how cause the problem.

second do an scan with otl and post the result here so our malware expert can have look on it.

http://oldtimer.geekstogo.com/OTL.com

Download OTL to your desktop.
Double click on the icon to run it. Make sure all other windows are closed to let it run uninterrupted.
When the window appears, underneath Output at the top change it to Minimal Output.
Under the Standard Registry box change it to All.
Check the boxes beside LOP Check and Purity Check.
Click the Run Scan button. Do not change any settings unless otherwise told to do so. The scan wont take long.
When the scan completes, it will open two notepad windows. OTL.Txt and Extras.Txt. These are saved in the same location as OTL.
Please copy (Edit->Select All, Edit->Copy) the contents of these files, one at a time, and post it with your next reply.

good luck.