Scott Hanselman's ComputerZen.com

If you're going to put up an error message, try to make it one that the user can DO something about, and try to make it unambiguous. A good error message takes work, and error handling seems to be one of those things that gets worked on last.

A few weeks back I installed Tim Heuer's excellent Foxit PDF Preview Handler for Outlook 2007. Worked great. I had (fervently) lamented the slowness of Acrobat, and folks in the comments - including an Adobe employee - commented that Acrobat 8 was way better and way faster than before. I figured today I'd give Acrobat 8 a try on Vista since Ryan Gregg just released a PDF Preview Handler that uses Adobe's ActiveX SDK.

Acrobat 8 on Vista is supposed to be nice because you get Thumbnail support and Search-ability for PDFs. I fired up the installer and was greeted with this error:

Certainly they could have figured out if the drive was full by asking the drive if it was full. Instead, this error says (basically) "something went wrong writing to a file, and I'm not sure what. Go ahead and see what you can do about it, user."

So what does user do? Well...

• "Gosh! Is my hard drive full? How do I figure that out? Maybe My Computer:
  
  Nope, it's not full.
• Permissions? Well, this is where Mom stops. How does she know where the Temp folder is? Heck, how does any user? I went to a command line and typed ECHO %TEMP% and was told C:\Users\Scott\AppData\Local\Temp, but it turns out that's not true! Acrobat (actually Netopsystem's Feed Squisher Installation Stuff) writes to C:\Users\Scott\AppData\LocalLow\Temp.
  LocalLow? What's that?
  Certainly I can either check the properties and permissions on that folder, or I can use icacls which tells me I do have permission:

  C:\>icacls \Users\scott\AppData\LocalLow
   \Users\scott\AppData\LocalLow ScottPC\Scott:(I)(OI)(CI)(F)
   NT AUTHORITY\SYSTEM:(I)(OI)(CI)(F)
   BUILTIN\Administrators:(I)(OI)(CI)(F)
   Mandatory Label\Low Mandatory Level:(OI)(CI)(NW)

  As an aside, there's a great blog post on Vista and IL (Integrity Levels) over on Joanna's Invisible Things.

Adobe's installer is trying to be clever and it's first squishy installer unpacks the real MSI installed into a folder that installers that will be elevated don't have access to. This happens on machines, like mine, that have UAC (User Access Control) turned off. Then, after the unpack/install files the temporary files are deleted.

Solutions

1. I can certainly try to grab the files by copying them out before I dismiss the dialog.
2. I can turn UAC back on. Nah.
3. I can also unpack the Setup Files from the Netopsystem's package myself manually via (someone remind me what Netopsystems is good for again? Are their files so small that they are worth this pain over ZIP? Or just the MSI itself? I've only ever seen their stuff in Acrobat.):
   
   AdbeRdr80_en_US.exe -nos_s -nos_ne -nos_oC:\Users\Scott\Desktop\AdobeReader8
   
4. I can wait until this is fixed.

Adobe's known about this, surely, at least since December. Why isn't #4 an option here in late March?

Either way, I got Acrobat 8 install eventually and it IS faster and it works great with Ryan's Preview Handler. Now we can choose between either Acrobat or Foxit and have Preview Handlers for both. Huzzah!