I can't download any attachments from gmail anymore, not in IE nor chrome. I always get the message that the attachment 'contains a virus and is removed'. Problem started when I installed AVG, but stays now I removed that.
What to do?

what version of windows are you using ,
have you run any anti spyware program like malwarebytes,or superantivirus

Vista 6.0, quickscan with Malwarebytes gave no result.

I always get the message that the attachment 'contains a virus and is removed

any indication in the popup as to what program is making this decision . or is it just a general windows box .you removed AVD did you replace it yet with an antivirus program .
I just uninstalled AVG from a win7 computer and boy did it take long to get rid of it all ,check control [add and remove]PROGRAMS to see if there is any rementanta of AVG

Can you go to another computer (friend's computer, public library, Internet cafe, etc.)? Perhaps you can go to another computer and download the attachment to a USB drive. If you can download from another computer, then you know the problem is not with Gmail, it is with your computer.

If the problem persists on another computer, then you know the problem is with Gmail, or your account, or perhaps just that particular attachment. In that case, you may have to find a way to deal with the problem email.

Try a few things to narrow down the problem.

Try the 'AVG REMOVER' tool, to clean out remnants left after AVG uninstall. Then run your Malwarebytes again. Dont forget to re-install AVG or similar

@caperjack: just a general windows box, all of AVG seems to be gone
@DavidB: no problems with other computer

@caperjack: just a general windows box,

is there an options tab in the box that gives option to save the file and not delete it , i don't use vista nev have really ,but i do get this type of message with win8 and i get the "more options tab" and click it and say save anyway .

if it was only happining in one Browser i would it was a browser security setting , you could try going to the browser option/tool section and resetting security to defaults security

I have it with IE and chrome and choosing other options doesn't help

then i would sort of lean towards you having a virus on you computer but i could be wrong

Hey "Tovak",
Do you sure that you removed AVG. This kind of meg come out because of antivirus tool or any malware detection tools. So if you installed any kind of malware antivirus tool, please disable it and download your attachment.
But I think no one recommended to do like that. But choice up to you.

Disable all security related tools. If it is not work , clean your registry and try to do it...