steps listed are in order that they should be done.
start with Control Panel|Add/Remove Programs
go into the Start|Control Panel|Add/Remove Programs. find the entry for your software. if it is there, click the uninstall remove or uninstall button.
try uninstaller file
look for uninstall or unwise in the start menu|programs. if it's not there or it doesn't work, then bring up a Windows Explorer. click on Start|My Computer or double-click on my computer on the desktop. make sure the folders button is depressed. expand C: on the left-side pane by clicking on the little + inside the square box in front of C:, expand Program Files, look for your program. it could be under a company name instead of the program name. expand that directory in the left-side pane. browse around to find the uninstaller. it could be named unwise.exe or uninstall.exe or unins.exe. double-click on it.
it is quite possible the only thing you will find is setup.exe, in which case you must run setup /u I think, so bring up a command-shell (windos-logo-key+R cmd), cd \ and Enter. and then use the cd command as many times as needed to cd into the directory in question, cd meaning change directory. when you get to the directory that contains the setup file, do setup /u - this may work and it may not do an uninstall - see if it does.
the windows logo key is the flag key between Ctrl and Alt.
unregister ActiveX controls
WARNING/disclaimer: messing with the registry is not recommended by Microsoft or by me. if you ruin your machine, you do it at your own risk.
do this from the command-line. for every directory in that program, you should do this from a cmd.exe shellfor %x in (*.dll *.exe *.ocx) do regsvr32 /u %x (note - you shouold be sure that you are in c:\program files\somedir - the location where the program resides. avoid c:\windows at all costs
remove bogus add/remove programs entries
WARNING/disclaimer: messing with the registry is not recommended by Microsoft or by me. if you ruin your machine, you do it at your own risk.
If there is an entry in Add/Remove programs, but it doesn't do anything or it gives an error, it's time to remove it, or try reinstalling the program.
to remove the entry, do the followiung: if you are in nt/2000/2003/xp/vista/7 (nt-family OS), start up regedt32 by doing windows-logo-key+R regedt32. If you are on win95/98/me, start up regedit by doing windows-logo-key+R regedit.
go to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall and search for your software entry. when you find it, deleting it will remove the bogus add/remove programs entry.
remove startup entries
WARNING/disclaimer: messing with the registry is not recommended by Microsoft or by me. if you ruin your machine, you do it at your own risk.
to remove the entry, do the followiung: if you are in nt/2000/2003/xp/vista/7 (nt-family OS), start up regedt32 by doing windows-logo-key+R regedt32. If you are on win95/98/me, start up regedit by doing windows-logo-key+R regedit.
go to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run and search for your software entry - any eexcuteables that are in that program directory. when you find it, deleting it will remove the softweare from startup.
remove services
WARNING/disclaimer: messing with the registry is not recommended by Microsoft or by me. if you ruin your machine, you do it at your own risk. not knowing anything about services and which are system services can lead to a broken system!
services are trickier. often the services are installed by the program name followed by install or -install to remove them you probably should try something like remove or -remove from the commasnd-line. to see what the services are, go through start|control panel, turn on classic view, double-click on administrative tools, double-click on services. look for services that might have to do with your program, if any. if you find any, write down the name of the service. stop the service. change the starup of the service from auto or manual to disabled. try to remove it. if it attempts to start up again, stop it or do an end-task via the task manager (ctrl-alt-del), whichever works. when you are able, rename the .exe to .ex so it won't execute.
pull up regedit or regedt32, whichever is appropriate for your machine (there is a difference in results when it comes to services!). go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services and search for your entry which you just wrote down. you may need to do an Edit|Find. when you find the service entry, delete the registry key for that service, or as much as you can out of it. you may not be able to get it all.
reboot/restart the system
delete the files
delete the files for the program in c:\program files\somedir