Aitrusskyy welcome to Avast!
I do not let CCleaner to handle Avast! files temps or no temps. I let Avast! to do his own cleaning. However, it is obvious that you got too many unpxxxxxx.mdmp files. These files are created by Avast! when it encounter problems within itself so they are dump files. I can not see the dates of the files so I cannot tell you if they are being created or were created in the past. If they are being created, dates are recent, it is better to reinstall Avast! clean. You said you got the laptop 2 weeks ago. is it brand new ? Did you properly uninstall the AV, even if it was a trial inactve version, it got before installing Avast! ?
Install from scratch:
1.) Very important to remove all remains of other AVs installed before Avast. Use this site to execute uninstall utilities for other AVs.
http://singularlabs.com/uninstallers/security-software/
2.) Download and save to your desktop aswclear.exe
3.) Download and save a fresh copy of Avast!.
http://files.avast.com/iavs5x/avast_free_antivirus_setup.exe
4.) Open Avast! > Settings > Troubleshooting > Uncheck " Enable Avast! self-defense module ".
5.) Uninstall Avast! normally through Control Panel > Programs & feature ( Vista, W7 ) or Add and remove programs ( XP ). Reboot. If you can not complete this step, continue with step # 6
6.) Even if you were able to uninstall Avast! in step # 5, it is important to run aswclear.exe in safe mode for any Avast! you may have had before,e.g. v.6 o v.7, and then for v. 8. Reboot into normal mode after uninstall.
NOTE: aswclear has the ability to make your system go into Safe Mode. Just run it in normal mode and follow instructions.
7.) Reinstall fresh copy of Avast! and reboot.
Be aware. Avast! will offer Chrome during installment. Remember to opt-out if you do not want it.