Firefox wont install extensions

This could just be me being stupid but when i try to install any Firefox extensions such as "Fasterfox" and "Adblock" i get the message at the top of the page saying "software installtion is disabled... ".
I am running Firefox 1.5.0.2 and have tried changing the installation settings under options but to no avail.
Any help would be great.

Thanks,

Alex

 

For your safety, installations for many sites have to be allowed. You should see a yellow band below your toolbars, with a "Options" on the right side, and, you can allow the site. These security measures may be an overkill, but should slow you down. Thunderbird 1.5 has a very irritating way of handling newsletters (comments are encouraged). You first have to click on a No Scan button (how am I supposed to know that the New York Times newsletter is or isn't a scam?). Then you have to click on the same button which has changed to View Images.
But, basically, one has to think.

 

I'm trying to download the addons from Mozilla's official site which is listed as one of the allowed sites to download software. However, even if i turn off the option saying "warn me when websites try to install extensions or themes" i still get the same message.

 

Delete it, and then allow it again. Turning off the warning does not fix anything.

 

I tried removing it and adding it but nothing happened. I can download things normally off sites using the download manager but when i click on a download link in the Mozilla Extensions page i get the yellow toolbar at the top saying installation disabled.
Any ideas?

 

* Firefox 1.5: If you previously disabled this option and then updated to Firefox 1.5, the disabled setting will be carried over. Since the option to enable software installation no longer exists in the UI, you will need to use about:config to reset the "xpinstall.enabled" preference to the default "true" value (bug 310737). These step-by-step instructions should fix the problem:

1. Type about:config in the Location Bar and hit enter.
2. Type xpi in the Filter box and find xpinstall.enabled in the list.
3. Make sure its value is set to "true" (double-click will toggle).

 

Thanks, All2kool!

alex98uk's issue has been frustrating me too and your instructions did the trick. I want to emphasize that in your step 2, one needs to type xpi in the Filter field at the top of the about:config page instead of using the Ctrl-F method that one may normally use for finding text on a web page. (I glossed over your instructions and tried the Ctrl-F method first without success.)

I just installed the update to McAfee's SiteAdvisor extension after following your excellent instructions and the update worked great!

BTW, I recommend SiteAdvisor to all Firefox users concerned with avoiding malicious web sites.

Thanks again, All2kool!

EDIT: Alternatively, one can simply scroll all the way to the bottom of Firefox's about:config page to find the xpinstall.enabled entry.

 

So, this is, most likely, a carryover from a Profile setting. No wonder that I never ran in such problem, since I will create new profiles, and, never bother with uninstalling/reinstalling the program. But, it is good to know about this, as I would have never thought of looking in my preferences.

 

You appear to be correct, Westside.

I think All2kool pasted his/her instructions from here:
kb.mozillazine.org/Unable_to_install_themes_or_extensions_(Firefox)