this is either a virus, or your comp. is being hacked: i would open up task manager & shut down I.E 1st.
it could also be other spyware, have you tried all the spyware mentioned on this forum?
then after you run those, i would boot-up to safe mode, then start/run/ type "msconfig" w/out the quotes.
then go to startup tab, & uncheck any of the things you mentioned poping up. (iexplore.exe/hostx.exe/docc.exe) uncheck these in there.
then after doing that, check the registry: run folder, and the run once folder, to see if any of those mentioned above are in there....if they are delete them from it, that should take care of it.
here is the thread for the spyware programs: