Unknown Error on Process.start

I am getting an Unknown Error message when calling process.start.  My code is below.  I have copy and pasted the filename into the Run prompt and IE does launch so I know that is valid, I have also pasted from the clipboard into the address bar and the URL is valid.

System.Diagnostics.Process process = new System.Diagnostics.Process();
process.EnableRaisingEvents = false;
process.StartInfo.FileName = @"C:\Program Files\Internet Explorer\iexplore.exe";
process.StartInfo.Arguments = url;

I do have a try/catch around the code, and there is no inner exception.  The error message I get is "Unknown error 0xffffffff".  This is running in a desktop app, and used to work.  I don't know what has changed on the computer in the last 3 months to make it not work, but the code did not change.
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AlexFMConnect With a Mentor Commented:
Try to run directly URL:
process.StartInfo.FileName = url;

This will work like ShellExecute, running program associated with file name. For URL, this is Windows Explorer.
Shakti109Connect With a Mentor Commented:

Have you applied any service patches or operating system updates to the system(s)?

A change in security (or tightening of security policy) will definately affect your ability to do external program launches.

In effect, you are doing what a web pop-up does.
To test and see if it is limited to internet explorer you could try :

System.Diagnostics.Process process = new System.Diagnostics.Process();
process.EnableRaisingEvents = false;
process.StartInfo.FileName = @"C:\windows\system32\calc.exe";

If calc.exe (the system calculator) works and the call to internet explorer does not, you may have a problem with the security settings.

If calc.exe does NOT work, there may be a system policy preventing launching of applications BY an application without some kind of impersonation or security rights.
SkipFireAuthor Commented:
AlexFM - your suggestion did function, however it pops up in the already open window, I need it to open into a new window which is what happens when you do "iexplore <url>".
Shakti109 - I still get unknown error with calc.  How can I determine if it is a policy change?  I have not changed the policy on my machine, but the domain admins could have pushed out a new policy to the domain.

Still need help on this one, but thanks for the help so far guys.
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I have tried this (opening the calculator) under several user contexts on a test machine and am able to fire up the calculator process under all of them.

Hrm...When you say "unknown error", is that what the error text says?

SkipFireAuthor Commented:
The error text is unknown error.
SkipFireAuthor Commented:
The code is now executing without me having changed anything.
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