I have tried to remove a the "Admin" word in this string
1H|\^&|||ARCHITECT^8.10^F3453010030^H1P1O1R1C1Q1L1|||Admin||||P|1|20150511083525
1D
with this regex
[^\w\b(Admin\])\b.-]+
and the output is 1H|ARCHITECT|8.10|F3453010030|H1P1O1R1C1Q1L1|Admin|P|1|20150511083525|1D
it does not remove the Admin word.
output desired:
1H|ARCHITECT|8.10|F3453010030|H1P1O1R1C1Q1L1|P|1|20150511083525|1D
i need help to improve the regex :(
Basically your regex should be like this
string input = @"1H|\^&|||ARCHITECT^8.10^F3453010030^H1P1O1R1C1Q1L1|||Admin||||P|1|20150511083525
1D";
string pattern = @"([^\w]*Admin[^\w]*)+|[|\\^&\r\n]+";
string replacement = "|";
Regex rgx = new Regex(pattern);
string result = rgx.Replace(input, replacement);
([^\w]*Admin[^\w]*)+|[|\\^&\r\n\s]+Not necessary to use regex here. You can use Replace function;
yourString.Replace("Admin|", string.Empty);
If using Regex is important for you - try this variant:
Regex r = new Regex(@"\bAdmin|\b");
var output = r.Replace(s, string.Empty);
100% working
Regex.Replace(@"1H|\^&|||ARCHITECT^8.10^F3453010030^H1P1O1R1C1Q1L1|||Admin||||P|1|20150511083525 1D", "Admin", "",System.Text.RegularExpressions.RegexOptions.IgnoreCase);
changes :
1: @ before string and
2:System.Text.RegularExpressions.RegexOptions.IgnoreCase
Admin) to \|Admin\|' to remove the vertical bar as well. Then add |\||` to remove "empty spaces" and exchange with |. I.e. "\|Admin\||\||" as regex (2nd argument) and "|" as replacement string (3rd argument). It's not perfect because if Admin, or an empty space, is in the begining or end of the string, it won't work. It's possible to fix, but if it isn't necessary, I don't want to complicate it further ;)You can do this simply via
\|*Admin\|*
You can remove using this regex and replace by |.
See demo.
Here is a 2 step solution: use your regex (with | added to the negated character class) and \bAdmin\b as an alternative (in your regex, it was not treated as a sequence of characters, but individual character a, d..., \b inside a character class matches a backspace symbol, not a word boundary) to replace with | and then join the string back:
var str = "1H|\\^&|||ARCHITECT^8.10^F3453010030^H1P1O1R1C1Q1L1|||Admin||||P|1|20150511083525\r\n1D";
var res = string.Join("|", Regex.Replace(str, @"[^|\w.-]+|\bAdmin\b", "|").Split(new[] {"|"}, StringSplitOptions.RemoveEmptyEntries));
Result: 
Update
You can also replace that all with one pass using the following regex:
\W*Admin\W*|[\\|^&\s]+
See demo
