Something like this should do it:
string val = "name="40474740-1e40-47ce-aeba-ebd1eb1630c0"";
Match match = Regex.Match(val, @"'([^']*)");
if (match.Success)
{
string yourValue = match.Groups[1].Value;
Console.WriteLine(yourValue);
}
Explanation of the expression '([^']*)
:
' -> find a single quotation mark
( -> start a matching group
[^'] -> match any character that is not a single quotation mark
* -> ...zero or more times
) -> end the matching group