Existing exchange installation re-join to domain

Question

Hello Everyone,
I'm just trying learn by doing, amateur with active directory and a complete newbie to exchange.
Here's the scenario and issue:
Had setup a domain with a single DC
Had installed a separate server with exchange, configured and working internally.
Had to then re-install and setup the domain, so removed Exchanged server from domain;
Re-installed and configured domain
Rejoined Exchange server in to the domain.
Problem now is I can only log on to the exchange server in safe mode. I had thought that joining the server with exchange on it would do all the active directory entries it would have done at installation (falsely re-inforced by the fact that server sat
at "Applying computer settings..." for hours on end). Checked event logs while logged in on safe mode, and event log's is riddled with exchange errors.
So, could I save this server from losing the exchange data and make it functional again in this domain thus forth?
Thanks in advance.
EDIT 01:
Clarification; I have rebuilt the DC with exact same IP and DNS  configuration as previously. Obviously, if those things did change, there could be configuration issues that the exchange server already has, therefore I took specific care with these
information. Please also note that I cannot install or uninstall anything if I cannot log on in normal mode. At the moment I can only log on in safe mode. Currently it hangs at "Personalized Settings (Not Responding)...".
Honestly, from what I have seen in the even logs (may be I should post them here?) I have a hunch that not all (if at all) AD object were created when the I re-joined the machine to the domain. I wonder if there's a way:
1) I can get past the point where it hangs; then
2) Recreate the AD object that Exchange would have during installation (Powershell?) without actually uninstalling and re-installing exchange (and losing exchange data in the process - I know BACKUPS!!!) thus restoring the usual relation an exchange server
would have with an AD / DC server?

Answer 1

Hi! 
Try the following:
uninstall exchange completely
Install the Windows Server 2008 R2 operating system prerequisites
http://technet.microsoft.com/en-us/library/bb691354(EXCHG.140).aspx#WS08R2
On servers that will host the Hub Transport or Mailbox server role, install the Microsoft Filter Pack
http://www.microsoft.com/downloads/details.aspx?FamilyId=60C92A37-719C-4077-B5C6-CAC34F4227CC&displaylang=en
Start the Exchange setup again:
Step 1 & 2 are already completed because you have installed the required features using the previous step.
Click on Step 3 and Choose Install languages only from the DVD 
Now click on Step 4: Install Microsoft Exchange
On the Introduction page, click Next
Accept the License Terms and click Next
On the error reporting page select if you want to enable the error reporting feature or not, then click Next
If you enabled it, Microsoft Exchange will automatically send error reports to Microsoft. This helps Microsoft improving their products.
On the Installation Type page, Select Typical Exchange Server Installation. A typical installation consist of the Client Access, Hub Transport, and Mailbox server roles, along with the Exchange Management
Console
If you want to customize your selection, then click on Custom Exchange Server Installation
Here you don't need to select the option Automatically install Windows Server roles and features required for Exchange Server, as we already installed these roles and features in a previous step using PowerShell and restarted
our server.
On the Organization name, Type your organization name and then click Next
If the server is facing external access then type the name that your users will be using to access your mail server from the internet. For example, my users will be able to check their mails using any browse by typing http://mail.elmajdal.com
On the Customer Experience Improvement Program, select if you want to join the program or not and then click Next
Exchange Readiness Checks will start to check if all prerequisites are setup and installed, and will report to you if you have any prerequisites missing 
The only warning you will receive is that Exchange Server 2010 setup will prepare your Domain for Exchange. The domain preparation operation will start once you click on Install .
Make sure the user you are using to install Exchange is a domain admin, enterprise admin, schema admin. Make sure also that you are logged into the computer using your domain user, and not using a local computer account .
Exchange installation will start
Installation will be completed. Click Finish
You will be notified that its better to reboot the server after the installation is completed, as setup has made changes to the operating system settings that require a reboot to take effect.
Exchange Management Console will open. and you can start configuring your server, which we will discuss in future articles.
 Source:http://www.elmajdal.net/ExchangeServer/Installing_Exchange_Server_2010_SP1_on_Windows_Server_2008_R2_SP1.aspx
I'm looking for alternatives to the solution you have provided, however, let's say I wanted to explore this option, any ideas on how I can get past the "Personalized Settings (Not Responding)..." part described in my edit to my original post? Thanks