Why do I get 800A0034 errors?

When using FileSystemObject in JScript, you might see this: 
 

Server object error 'ASP 0177 : 800a0034'   Server.CreateObject Failed

 
One reason could be forgetting to double up backslash characters in local paths. Since \ is an escape character in JScript, the following line: 
 

var f = fso.openTextFile("c:\foo.htm");

 
Will actually get interpreted incorrectly, since JScript will be trying to render a "\f" character. So to fix, use the following syntax: 
 

var f = fso.openTextFile("c:\foo.htm");

 
If you are using VBScript, you might see this error: 
 

Microsoft VBScript runtime error '800a0034'   Bad file name or number

 
One possible cause is forgetting to specify a filename in a FileSystemObject method, e.g. 
 

fso.copyFile "c:\boot.ini", "c:\backup\"

 
Notice that no filename was specified in the second argument. To correct, make sure both the source and target file has a name. 
 
Another possible cause is attempting to use FileSystemObject to load a file from a URL. FileSystemObject only has the ability to read *local* files, so if you want to process a text file that resides on another server, see Article #2173.