Throughout my work over the years, I have run into this problem quite a few times and I have come to realize that it is not a trivial dilemma. The login process is different depending on the operating system and has changed with recent Windows 2008 server/Vista developments.

The first step in the login process for a 2003 server is with the Interactive Login Process explained in detail: http://technet.microsoft.com/en-us/library/cc780332(WS.10).aspx

Once you start looking at the referenced document, you start to understand that logging in is not really as easy as Ctrl + Alt + Del, type username and password, and you are done. This is just the starting point to a pretty complex task that will allow the user to login or not.

What could be slow then?

The first thing you should do is gather some information:

- Check if all your users experience slow logins, or whether it is just one specific user.

- Is this happening during certain hours of the day or all day?

- If you have Citrix, does an RDC login have the same problem?

- If it only affects a single user, I would start looking at the user profile to see if it is set as a roaming profile. If the profile is roaming, you could look at the size of the profile. To check a profile type (roaming, local, mandatory) and size, open the control panel, click on ‘System’ and the ‘Advanced Tab’, select ‘user profile’ and you will see the size listed for all profiles on the computer you are on. (You can also use triCerat free Profile Analysis found at http://www.tricerat.com/pat_dl. This tool will list all user profiles in your network and give you a good overview of their size, location and type.)

- If the profile is large, that could be the cause of your slow login time. If so, see what in the profile is causing this. Is it a large file on the desktop or something similar? If you find anything, try to move that file out of the profile and see if this speeds up login (also consider using folder redirection to place those large files on the network instead of within your roaming profile, http://www.tricerat.com/blog/222).

- If the profile is small and it is still taking a long login time I would consider turning on logging of the user environment load. This log can show you in detail what happens during login, what file is taking long time to load, if DNS/WINS is slow or if your Group Policy loading is preventing the user to login fast and easy. This article tells you how to enable this: http://support.microsoft.com/kb/221833

- Login scripts may also be a cause of slow logins. I have been in contact with many companies over the years that do everything with login scripts: map network drives, assign printers, create registry keys, copy files, and more. This is okay when everything is working, but it is a nightmare to troubleshoot. I was recently speaking to a Citrix Consulting Engineer that had been visiting a customer with five-minute login times per user. He did some troubleshooting and found that it was the login script that took five minutes to run! They decided to investigate what the script was doing and find out if there were any way they could make it more efficient. After they reviewed the script, it turned out it accomplished almost nothing! Having a complex login script also causes a single point of failure because if the admin that wrote the script decides to leave the company or worse, it can be very hard to get a grip on the script.

As a summary of this little article, you could say that logins seem easy enough for someone that has not really investigated the process and its dependencies. triCerat can help you achieve a more efficient login process with Simplify Suite. The Simplify Suite can manage applications, printers, registry values, folder redirections, and drive mappings through easy drag and drop operations on one easy to use management console. The Simplify Suite also comes with support so you can ensure your investment is protected and admin independent.

Source: http://www.tricerat.com/blog/254