Did you use the removal tools for AVG and Avast as instructed?
I have to say that it seems that the problem is "deeper".
Clean your web browser's cache, together with "bad moods"
.
Download (yes, yet again, anew)
1_ AVG removal tool.
2_ Avast removal tool.
3_ latest Avast version.
4_ latest drivers version (for exact hardware model and for exact OS, SP and x32 / x64 combination).
Then please remove your display drivers (Add/Remove programs, reboot, Device Manager, reboot). The goal is to use Windows default display drivers. Yes, basic resolutions and capabilities, but standard and working. If you find older versions of your specific display drivers, don't use them. Much better yet, uninstall them too (it takes time and is longer to explain in the forum, so I skip this). Just be sure you use the default standard Windows display drivers only and nothing more (not add-ons nor special tools from your display card manufacturer or any other party, specially if they start with Windows boot).
It is also important to remove any remnants from your display drivers. So when uninstalling from Device Manager, any file that Windows says it is not necessary anymore, please accept the deletion of it. Then reboot.
Don't panic if the desktop shows strange. Leave it alone. All should be OK when you finally install the latest drivers.
Using the standard default Windows display drivers, boot into Windows Safe Mode. Run the AVG removal tool. Reboot again into Safe Mode. Run Avast removal tool for 6.x (select the correct folder). Reboot again into Safe Mode. Run Avast removal tool for 5.x (select the correct folder, if there is a different old "Alwil" folder).
Now reboot into normal mode. With admin permissions (elevated), run Avast installation. Once it finishes, reboot. If it works (meaning, no BSOD, nothing else), reboot once more (please, do NOT skip this).
No BSODs? Install your re-downloaded display drivers. After that, reboot TWICE (please don't skip this).
For each reboot, I mean to get to the Windows user's desktop (not only the "Windows welcome screen").
No BSODs? Only now we can finally start looking into potential "Hackshield and Avast" conflicts, or any other "only Avast related" problem.