Antispyware tools stall partway through and freeze computer

Why do so many antispyware tools stall partway through and freeze my computer? I have found that Malwarebytes, Superantispyware, and IObit Malware Fighter all satrt, but stop part way through file scanning, and end up freezing my computer. This is whether I start in Safe Mode or not. AVG and TDSSKiller are the only ones that don’t. I suspect I have some malware installed and that is is what is stopping these programs. I’m running Windows 7 on a Dell E74400 with a SSD.