First: The offending programs are being automatically started via Windows registry entries, etc., processed at boot time ... ie: HKCU entries or commands in your login's or the 'all users' start directory (ie: c:\Documents and Settings\All Users\Start Menu\Programs\Startup).
To stop them from firing up you must update the start-up directory and/or the registry to deactivate/delete the offending entries (preferably update the registry via a safe registry editing tool like "Start-up Control" (http://www.mlin.net/StartupCPL.shtml)).
a) You may have to start/boot the PC in 'safe' mode to get to things.
b) I always move start-up directory entries into a temp directory (rather than just deleting them) to deactivate them until I have re-tested the system.
Second: After the start-up/registry entries have been deactivated/deleted, re-start/boot the PC (in your normal mode).
Hopefully, everything on your PC now runs fine (and maybe even a little faster) ... test the PC/your important applications before you go any further.
Third: If new problems do appear/occur, use the start-up directory copies/registry backup to get back to where you were (ie: at least no more harm done).
Forth: If the offending programs are not executing and all the other stuff on your PC still runs fine, you should be able to delete the unwanted programs (and, if desired, their home directories, the backup copies you made, etc).
-- Never, never, ever delete/change a registry entry unless you are sure you know what you are doing and you know you have a good back-up!
-- A good registry editing tool should create a backup of the just registry entries being changed so you can undo things if you make a mistake!
-- Never delete files or directories if you are not sure what they do ... especially any files/folders found in what may be system required directories (ie: "Windows", "Documents and Settings", "Application Data") and major hardware/software vendor directories (ie: "AMD", "Intel", "HP", Dell", "Sony", "Microsoft", etc)!
-- Generally try using the software products own 'uninstall' to clean-up (most) registry entries & files associated with the product; HOWEVER, if you are trying to remove a program you know to be a virus, trojan, etc., the uninstall that came with it may just make matters worse!
-- Always uninstall one anti-virus and/or firewall program before installing a replacement! Otherwise if you install a new product and then uninstall the old product you may screw up the new product (ie: the 'new' products install may overlay parts of the 'old', then the 'old' products uninstall may end up deleting parts of the 'new' not knowing the part wasn't an 'old' part)!
Use proper care and you'll have good luck.