'There was an error while completing the setup process'

I’m having difficulty installing avast! on my HP Pavilion g series laptop. I believe my system to be infected with at least one virus and I intend to get a third scan using avast! in case my other two programmes (malwarebytes and MSE) missed anything. The error ‘There was an error while completing the setup process’ appears after running the setup exe. Any help is appreciated.

Computer Specs are as follows:

Processor: Intel (R) Core ™ i3-2330M CPU @ 2.20GHz
Installed Memory (RAM): 4.00GB
System Type: 64-bit OS

Setup log is as follows:

18:05:24Infoinstcont[1364,1384]–
18:05:24Infoinstcont[1364,1384]2015/04/05 18:05:24 START: Avast installer/updater
18:05:24Infoinstup[1364,1384]Command: ‘“C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\instup.exe” /edition:1 /prod:ais /sfx:lite /sfxstorage:C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144’
18:05:24Infoinstup[1364,1384]CPU: Intel(R) Core™ i3-2330M CPU @ 2.20GHz,4
18:05:24Infoinstup[1364,1384]OS: Windows 7 SP1 x64
18:05:24Infoinstup[1364,1384]Memory: 17% load. Phys:3406196/4140912K free, Page:4194303/4194303K free, Virt:4115880/4194176K free
18:05:24Infoinstup[1364,1384]DISKs: C:\ - 296GB free / 446GB total
18:05:24Infoinstup[1364,1384]DISKs: D:\ - 1GB free / 15GB total
18:05:24Infoinstup[1364,1384]DISKs: E:\ - 0GB free / 3GB total
18:05:24Infoinstup[1364,1384]Running module version: instup.exe - ‘10.2.2215.880’
18:05:24Infoinstup[1364,1384]Running module version: Instup.dll - ‘10.2.2215.880’
18:05:24Infosimutex[1364,1384]Checking for the mutex ownership.
18:05:24Infosimutex[1364,1384]The mutex is signaled. We are owners of the mutex.
18:05:24Infoguiwizard[1364,1384]Running module version: HTMLayout.dll - ‘3.3.2.170’
18:05:24Infoguiwizard[1364,1384]Loaded module version: C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\HTMLayout.dll - ‘3.3.2.170’
18:05:24Infoguiwizard[1364,1384]Setup gui was successfully started.
18:05:24Infoinstupcore[1364,1384]Setup update has started.
18:05:24Errorservers[1364,1384]Load: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def’ has invalid signature.
18:05:24Infoservers[1364,1384]External pseudo definition loaded with name ‘Fallback server (invalid servers.def)’.
18:05:24Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:25Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 1
18:05:25Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:27Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 2
18:05:27Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:29Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 3
18:05:29Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:31Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 4
18:05:31Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:33Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 5
18:05:33Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:35Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 6
18:05:35Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:37Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 7
18:05:37Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:40Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 8
18:05:40Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:42Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 9
18:05:42Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:44Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’ has been downloaded but it has invalid signature. Next try: 10
18:05:44Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:46Errorpkgengine[1364,1384]DownloadPackage(download): ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\servers.def.vpx’, ip: 172.233.184.164, has failed with code: 40961 (0x0000A001) [Invalid signature]
18:05:46Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:46Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 1
18:05:46Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:48Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 2
18:05:48Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:51Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 3
18:05:51Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:53Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 4
18:05:53Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:55Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 5
18:05:55Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:57Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 6
18:05:57Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:05:59Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 7
18:05:59Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:06:01Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 8
18:06:01Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:06:03Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 9
18:06:03Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:06:06Errordldwrap[1364,1384]GetFileWithRetry: file ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’ has been downloaded but it has invalid signature. Next try: 10
18:06:06Infoservers[1364,1384]ChooseServer: selected server ‘Fallback server (invalid servers.def)’ with current url ‘http://files.avast.com/iavs9x/’ of type ‘URL_TYPE_DOWNLOAD_PROGRAM’.
18:06:08Errorpkgengine[1364,1384]DownloadPackage(download): ‘C:\Windows\system32\config\SYSTEM~1\AppData\Local\Temp_av_iup.tm~a03144\prod-ais.vpx’, ip: 104.67.56.102, has failed with code: 40961 (0x0000A001) [Invalid signature]
18:06:08Errorpkgengine[1364,1384]LoadLatestProdAndParts: download product file ‘prod-ais.vpx’ has failed. Status: 40961 (0x0000A001) [Invalid signature]

I'm having difficulty installing avast! on my HP Pavilion g series laptop.
in case my other two programmes (malwarebytes and MSE) missed anything.
[b] Why Using Multiple Antivirus Programs is a Bad Idea[/b] http://blog.kaspersky.com/multiple-antivirus-programs-bad-idea/
I believe my system to be infected with at least one virus
if so, free help with that is done in the[b] viruses and worms [/b]forum section you find a how to recive help guide at top in that forum section .... [b]Logs to assist in cleaning malware[/b]

Ok, thanks

I would run avastclear and try the offline installer for avast.
https://forum.avast.com/index.php?topic=168376.0