Adobe reader has an error code-invalid plug in-- i have vista. i can not open any pdf files.

What Plug-In?

Try uninstalling it, and get a full version, here is the link : http://adobe-reader.softonic.fr/telecharger

There's a discussion of this problem on Adobe's forum at
http://forums.adobe.com/thread/771034.
Maybe some of the ideas there will help.

Have you tried Foxit Reader? It's for .pdf files and I've had very good luck with it. Download it for free:
http://www.foxitsoftware.com/downloads/

tried up-issues (Adobe Reader 8.1.2+) and got the same error "invalid plugin detected. Adobe Reader will quit".

I fixed this error by following laborious steps described in the Adobe Technical Support Home.
Not sure if this helps you guys; but worth a try. Developers should say if this the real cause.

You can find these in the "plug-ins" folder. [C:\Program Files\Adobe\Reader 9.0\Reader\plug_ins]

"HAEvents32.api" is the main culprit. Along that, I removed "Helmant32.api" and "Helmbkmk32.api".
Without deleting these two, an error or two might come but still PDF will work. I tried all these combinations.

Note: Delete these files if present anywhere else in the system else they recreate themselves.

Thanks every one.

Make sure that adobe reader is installed in your PC.PDF files are read by adobe reader.so to open PDF files install the adobe reader in your PC.

Help with PDF Documents Some documents on Maine.gov are provided in PDF format. In order to view or print PDF documents, you need the free Adobe Reader. Generally, you will find an alternative format is also provided for the document, such as Microsoft Word, HTML, or plain text. If you cannot access a document in PDF format and there is no alternative version, please contact the agency or contact the Maine.gov webmaster for assistance.
Adobe PDF-to-HTML Online Conversion Tool
We've provided solutions for some common PDF issues below.
General Tips:

• If you are having trouble opening a PDF document, one of the first things to try is updating your Adobe Reader to the latest version. You may also need to update your browser if you are using an older browser.
• Additional support is available on the Adobe Reader Support Page (Adobe.com).
• You may also want to read Adobe's more detailed troubleshooting tips.

Problem 1: Blank Page in Browser You have selected to download a file and you receive a blank page with a "Done" message at the bottom of the browser. This may be because you do not have enough space in your temporary internet file folder to complete the download.
Solution: Internet Explorer: Tools> Internet Options> Temporary Internet Files> select Delete Files
Netscape: Edit> Preferences> Under Category on the left Advanced> Cache> click Clear Memory Cache
Problem 2: Blank Page "%PDF" You received an error message containing "% PDF" or you have received a blank page while trying to download. This is due to a problem with your web browser not opening .pdf documents correctly.
Solution: Adobe Acrobat Reader 5.0: Edit> Preferences> General> Options> Web Browser Options> make sure the Display PDF in Browser box is not checked.
Adobe Acrobat Reader 6.0 and newer: Edit > Preferences > Internet > make sure the Display PDF in Browser box is not checked.
Problem 3: "Error Locating Object Handler" You receive an error message that says "Error Locating Object Handler" while trying to download a document. This is because there is a dependency with a plug-in for Adobe Acrobat while using Internet Explorer.
Solution: Please go to the following website for detailed instructions: http://support.microsoft.com/default.aspx?scid=kb;EN-US;q262213
Problem 4: Unable to Print You have successfully downloaded the pdf, can view it on your computer screen but are unable to print. This is due to a post script error with your printer.
Solution: In any Acrobat Reader program: File > Print > check the Print As Image box > OK
Problem 5: "Adobe Reader could not open file" You received the error message "Adobe Reader could not open 'filename.pdf'" because it is either not a supported file type or because the file has been corrupted (for example, it was sent as an email attachment and wasn't correctly decoded).
Solution: Adobe Acrobat Reader 6.0: Edit> Preferences> Internet> make sure the Display PDF in Browser box is not checked.

INVALID PLUGIN DETECTED.

Go to C:\Program Files\Adobe Reader 9\Reader\Plug_ins\.....delete the Babylon folder. It worked for me!

Sounds like your files are not assigned to the correct program.

Open Windows Explorer and find a pdf file.

Right click on it and choose Open With...

Select Adobe Reader and check the box at the bottom that says:

Always use the selected program to open this kind of file.

Click OK.

All pdf files should then open in Adobe.

You can do the same with any other type of file by choosing the program you want to open it with.

Thanks for using Fixya.

Adobe Reader allows you to open PDF files. Download another PDF file such as: http://illiad.evms.edu/sample.pdf

If that opens, the problem is with the site.

Download the Adobe Reader 9 software. It's free from Adobe.