pages on google Chrome keeps crashing and gives a message like "Snap..."
btw, after my full scan failed, i tried a quick scan and it was super fast, it jumped from 5% to 50 then to 98%, and the speed was only stabilized at 98%
Sounds like malware. Could be it's interfering with or disabling McAfee, but GetSusp and Stinger should have picked it up. Alternatively, it could be a disk or file system problem, it's not possible to say without seeing it for myself. You may need to go to Support for this, and let them run you through the basic checks (although they're going to say uninstall/reinstall, I just know it).
If you can run chkdsk and sfc ("sfc /scannow"), do so. Check the state of your file system first.
Next, run Security Scan Plus - it verifies the state of your AV protection and checks for malware in any running processes. I know a lot of people don't like this little tool, but it can be useful sometimes. Like now.
Then run MVT to do a full check of the state of your installed McAfee product. If it's completely messed up you will have to uninstall it, run MCPR, and re-install.
Download and run Microsoft's Safety Scanner. It's a non-McAfee solution, but we want a second opinion here.
If you need support from McAfee the contact details are in the red bar at the top of the page.