Button click issue in IE 11

Hi,

i am working on the project which was created in vs2003 and then converted into vs2010. Everything is working fine on all browser but from last few weeks i am receving problem that website is not correctly working in IE 11.for e.g. some button click and autofill is not working.

I have checked the code and found that few asp.net control click event is not firing for e.g.

<asp:linkbutton id="lnkSignin" name="lnkSignin" runat="server">
<img src="images/API/Signup/LoginButton.gif" alt="Click here to login" width="78" height="23"
border="0" /></asp:linkbutton> 

This is working correctly on the IE 11.

<div style="margin-bottom: 10px; margin-">
<a href="Verify.aspx"><img src="images/API/Signup/Button_Verify.gif" alt="Verify Safety Key" width="78" height="23"
border="0" /></a>
</div>

I have read lot of blogs and tried what they have told us like:

1. Add .browser file
2. Add Metadata tag on aspx page
3. Add Metadata tag in web.config
4. Add patch for vs2010

Some blog suggest me to install the .Net Framework version 4.5 then i will work correctly (but i want to know is there any other way because we cannot install any framework/patch) on the server.

Can somebody help me what i need to do in this case.

here is the link of the website:

https://worksafe.api.org/