Recently a pop up appeared that said "Windows has blocked some programs from starting up" and when i clicked the message, windows defender comes up. I checked through the startup programs and in one of the lists is a "startup.exe" and Windows Defender says it didnt come with the system, and its in the "Publisher Not Available" category.

Heres the problem: the buttons "Enable" "Remove" and "Disable" are grayed out. Not just for setup.exe but for all the programs, I coudnt enable or disable anything in windows defender.

Another thing is setup.exe a virus, malware, spyware etc..? it says it didn't come with the system, and spybot and Ad-aware aren't detecting anything.

Have a look at this http://support.microsoft.com/kb/930367

That just shows me how to get to software and click the disable, enable and remove button. My problem is that those buttons are grayed out even in software explorer

Try an online virus scan. I can recommend
http://housecall.antivirus.com/

In order to get the Software Explorer Remove, Disable, Enable buttons to work, you first have to click on "Show for all users". You will get the UAC permission prompt, so say yes and do what you need to do.

John Hanley
Sugar Land, TX

that worked, thank you retexan