Loss of internet connection when downloading

I'm using Windows XP Professional and Internet Explorer 7. I have a home network I use to share files between this desktop and my Vista laptop, so I was told by other help forums that SP3 for my XP desktop would help me in establishing that network connection, and being able to access shared folders. I did install SP3 and the network is absolutely fine. However, I didn't try it before installing SP3 so I can't say for sure whether it helped it work or not. Anyway, that's just background information. My problem is that when I'm using IE7 on my desktop (with XP Pro), it works fine until I start a download. Once a download has started, it gets to around 25%, and then stops. When it has stopped, none of the tabs I've got opened in my current IE window works. They all have that green loading bar in the status bar but they never actually load or give me an error. They just load forever. It happens to all of the tabs. However, if I open a new window of IE, it loads fine. I can open as many tabs as I like in this new window and they all load fine and quickly. However, the old window never loads, and the download never carries on. It just stays where it is at 25%. It doesn't auto-cancel or close - it stays up but never moves forward. This is getting very annoying now, as I can't download anything. Has anyone got any ideas what might be causing this IE window-specific hanging of my internet connection, and why it wouldn't affect any IE windows? Thanks.

Problem like this are often caused by add-ons. I recommend you disable yours and see what happens. Got to Tools > Manage Add-ons > Enable or Disable Add-ons, wait for it to populate then disable any you have added. Alternatively, you can reset IE7 under Tools > Internet Options > Advanced