Windows 7: Windows 7 cannot open .zip files

I've been running into this problem for a few months now (I've had Windows 7 longer than that) and recently Windows 7 will not open .zip files if I was to download them from BaseCamp.

I used to be able to, but not in a few months.

I've already take the steps of downloading WinZip and 7-Zip and have the same problem. It won't open the files claiming that "Access to the Compresed (zipped) Folder 'C:\blah blah\.zip' is denied." Which is a bunch of manure because the files are not encrypted and they're not set to 'Read-Only', etc.

So if I request the files to be Skyped to me, Skype refuses to download them. So when I make another attempt to download the files from Skype, I have to change the name of the file, then it will download, and then I can open it without any problems.

Problem is, I use BaseCamp quite a bit and reliance on this system is high when it comes to downloading files. Windows 7 has become quite unreliable in opening these files (that and 7-Zip and WinZip).

The files that are uploaded to BC are coming from someone who uses a Mac, if that matters.

I hope someone can help me with this issue because it has cost me (and still does) time to try to work.

Thank you for your time.

What AV are you running? I don't know anything about BaseCamp but the files may contain viruses (virii?).

Try checking the AV history/ log to check if it has a report in there.

No viruses. These are clean files.

Is there no one else that can help me with this? I've had someone else download the files (they were Mac users) and they had no problem whatsoever opening them.

I've also consulted the company where the files are being stored and they too had no problems opening the files after downloading.

I'm suspecting a Windows bug and am not happy.

A good start would be posting a screenshot that everyone can open. You have a snipping tool in Windows 7 that makes this very simple.

It's most definitely not a Windows bug, as many people would have this issue. It is almost always a firewall/AV software package problem, or a NIC problem. You don't have your system specs filled in, but are you using an Nvidia network adapter, by any chance?

As for a screenshot. I've attached one here. This is what I get for trying to open a .doc file.

It seems the culprit of the problem has been found: McAfee SiteAdvisor had to be disabled in order for me to be able to open files of those specs. After disabling it from by browser, all works well, but I wish I can still use the SiteAdvisor.

Anything with the word McAfee in it is pure junk, so you won't be hurting anything by removing it.