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When I try to install Firefox, I get a "can not open output file" error. I was using Firefox before and it stopped working, so I uninstalled. Cannot re-install now.

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  • Last reply by ShayS

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When I try to install Firefox, I get a "can not open output file" error. I was using Firefox before and it stopped working, so I uninstalled. Cannot re-install now.

This happened

Every time Firefox opened

I tried to download firefox.

User Agent

Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; AntivirXP08; GTB6.3; .NET CLR 2.0.50727; MS-RTC LM 8)

When I try to install Firefox, I get a "can not open output file" error. I was using Firefox before and it stopped working, so I uninstalled. Cannot re-install now. == This happened == Every time Firefox opened == I tried to download firefox. == == User Agent == Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; AntivirXP08; GTB6.3; .NET CLR 2.0.50727; MS-RTC LM 8)

Chosen solution

When you click the download link on GetFirefox.com, you should be asked if you wish to Run or Save the file. If the described situation happens when trying to Run the download, try instead to Save it and put the file on your Desktop or a similar place where you are certain that you can find it again.

When the download is complete, try double-clicking the downloaded file in the normal Windows Explorer (browse your way to the file from My Computer). This should start the installation.

If you notice in the Explorer window that the file seems to be lacking the Firefox orange/blue icon, rightclick the file and select Properties. The picture should look somewhat like the attached picture (except that mine's in danish, but that is irrelevant) if saved correctly - if it does NOT look like this, please describe the contents or attach a screenshot of the box. Especially what it says under "File type" - it should be "Program"; if it's not, we'll have to look into what the problem could be here.


Slightly off-topic, your Internet Explorer seems to be quite a bit out of date (IE 6, where current version is IE 8), so I would strongly recommend that you try to run Windows Update to get your system updated. If this is a company system (like a Terminal Server thin client machine), this may not be possible, and your system administrator will most likely have to help you.

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Chosen Solution

When you click the download link on GetFirefox.com, you should be asked if you wish to Run or Save the file. If the described situation happens when trying to Run the download, try instead to Save it and put the file on your Desktop or a similar place where you are certain that you can find it again.

When the download is complete, try double-clicking the downloaded file in the normal Windows Explorer (browse your way to the file from My Computer). This should start the installation.

If you notice in the Explorer window that the file seems to be lacking the Firefox orange/blue icon, rightclick the file and select Properties. The picture should look somewhat like the attached picture (except that mine's in danish, but that is irrelevant) if saved correctly - if it does NOT look like this, please describe the contents or attach a screenshot of the box. Especially what it says under "File type" - it should be "Program"; if it's not, we'll have to look into what the problem could be here.


Slightly off-topic, your Internet Explorer seems to be quite a bit out of date (IE 6, where current version is IE 8), so I would strongly recommend that you try to run Windows Update to get your system updated. If this is a company system (like a Terminal Server thin client machine), this may not be possible, and your system administrator will most likely have to help you.

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It says application under the installer download and not program.

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Do you have a program like WinRAR? I had the same problem, saved the file on my desktop, and extracted the file on my desktop after the save then simply clicked the 'setup' that was extracted, and then it worked.