I have enabled remote desktop on Windows 8.1. When I try to connect using a windows 7 computer on the network it doesn't work using Remote Desktop Connection. However, it works when I send an invitation from windows 8.1 computer to windows 7 computer it works. The computers only connect through invitations. Is there a way to bypass the invitations?

Not sure since you did not provide much on the error level but look at this blog here:http://windowsitpro.com/windows-7/windows-7-sp1-can-now-connect-remotely-windows-81-and-windows-server-2012-r2

Invitations is Remote Assistance, not Remote Desktop.

You need to reduce the support level to allow older clients to connect.

Windows 7 support NLA unless am mistaken so was under the impression this was not the case and the error message for NLA is self explainatory so i hope if that is what he got he would let us know.

Hello,

For Remote Desktop, please make sure the following settings are set correctly:

1. Remote Desktop settings in System Properties.

2. The account used by remote must be in the Remote Desktop Group

Thanks,

How do I reduce support level??

Yes I have done that but it doesn't work

Windows 8.1 provides more security than Windows 7 which can make connecting to it remotely more difficult. 
1. Try temporarily turning off the Windows 8.1 firewall to see if you can connect. 
2. Do you have an account setup on your Windows 8.1 machine that has either Remote Desktop or Administrative access rights that is connecting from your Windows 7 machine?
3. Did you try the Update for Remote App and Desktop Connection that Frederick mentioned? Also in the diagram that Simon posted, please check the box for Network Level Authentication (NLA) that Frederick had previously mentioned. 
4. Take a look at Use Remote Desktop when Windows Firewall is on which may help and also Remote Desktop into Windows 8. (Note: this is not a Microsoft approved site so contents and location are not supported.)