Problems with downloads/anti-virus

[suzie82]

I'm a bit of a computer novice, so excuse me and please prompt me if I have left out relevant information and where I can find it.

I have been on holiday for 2 weeks and left behind my laptop and pc in good working order. They are on the same internet connection, one wireless the other wired - on virgin media broadband. The PC uses XP and the laptop uses Vista.

I returned yesterday, and immediately went to the antivirus on the laptop to update it as I was prompted to by the windows security shield. An error message came up saying it couldn't update, which I wrote down and have now misplaced. Since then I have not even been able to open the antivirus program (it is AVG). Because windows was telling me that there was no Antivurs in place, I decided to uninstall AVG and try to install it again. I was unable to as when I came to run, it said "File is corrupt"

I tried several other well respected antivirus programs (mcafee, avast etc) and all blocked me for similar reasons - mostly with the message "The Setup files are corrupted, please obtain a new copy of the program"

I then tried starting up the PC. Again as I tried to update the Antivirus program (Avast) and got the message "Last encountered error invalid file signature, setup will terminate" I also cannot update or download new software onto this computer.

The two are not linked in anyway except by the shared internet connection. No programs have been installed onto either other than updated versions of existing programs such as antivirus since the beginning of May (I checked in Control Panel).

Although unaffected at first, now when I try to open firefox on the laptop I get the message Exception... "could not convert javascript argument arg [ns]Supports.QueryInterface]" nsresult: "0x80570009 (NS_ERROR_XPC_BAD_CONVERT_JS)" location: "JS frame :: chrome://searchshield/content/overlay.js :: InitSDK :: line 473" data: no]

I also cannot open Facebook, although I could at first (I'm guessing I shouldn't have thinking about it now, but it's just a bad habit of browsing while waiting for Antivirus to update)

I'm at a complete loss as to what to try, if anyone can give me any pointers I'd really appreciate it.

[suzie82]

I have now found that I cannot update or download anything. I strongly suspect the internet connection as yesterday I took the laptop to the library, used their wireless network, and was able to reinstall the anti-virus program. At home the problem persists.

I've called my provider who say it can't possibly be the internet connection. I don't know what I'm talking about enough to argue with him, but I suspect that he doesn't know much more than me and is just a hired lacky reading from a script. Any help would really, really be appreciated.

[Greg]

Try this on XP http://www.microsoft.com/security/pc-security/malware-removal.aspx

Used to work well. I have done it in safe mode with networking enabled.

[jaydeee]

It looks to me like you are infected with computer virus or malware. try the following.
1. use Rkill, just google it. run it and let it run on your system, it will not take long. I will stop all malicious activities on your computer.
2. Update Avast. then scan your computer on boot time.
3. Install and scan using Malwarebytes.
4. clean your computer using ccleaner. this procedure may be executed before running rkill.

hope this helps.

[Kellee]

Unfortunately I am having a similar issue. I was afraid that it might be a virus or something. I will try your suggestions and see if that helps. Thank you.

[ItsFixed]

Kaspersky Anti-virus however is one of the big guys, as this particular solution has always been one of the favorites to win the competition all over the world. Its detection rate is amazing, with virus definition updates delivered every day.