[HELP] I have a problem with image uploading on internet.

Here's my problem.

It all started when I accidentally uploaded a 2MB> img on Disqus.
Now I can't upload images on the internet anymore. Be it PhotoBucket, pomf.se, etc.
Even a 150kb img failed to upload.
And imgur only allows me to upload a single image before it breaks down.

Any ideas? Already did some googling but I still can't figure out the problem.

PC : Window VISTA 64x
Antivirus : Avira

Always stuck during upload like so.


EDIT : I can upload normally on my laptop and phone. I think the problem lies with my computer.