I haven’t heard of this site, so no advice for you. What information do you want to know about your computer? PCpitstop offers free scans and I know they are safe to use. Of course they are trying to sell services beyond the free scans, but those are optional.
For free malware scans, look at MalwareBytes. Their free version works fine.
For free anti-virus, Avast or Microsoft Security Essentials would be my recommendations.