Have you trying to install SharePoint 2013 in a machine where you had SharePoint 2010 previously installed and removed?

If that is the case, you may get this error message ” Setup had detected previous versions of this product on your computer” while you install even though you removed SharePoint 2010 completely from your server.

Uninstalling SharePoint 2010 does not remove everything and there are still some items exist in the server like /14 folder , SharePoint Web Services Web application and its application pool in IIS but you also need to remove settings in regedit.  If you don’t this is what you will get
Setup had detected previous versions of this product on your computer. Setup can’t continue while these are installed. Please remove the previous version before restarting this version’s setup program. If you want to upgrade your existing content and services, you should review the upgrade documentation to determine the correct process to use for your environment.

Setup had detected previous versions of this product on your computer.

1. HKLM\Software\Microsoft\Shared Tools\Web Server Extensions\14.0

Delete all the folders under 14.0

2. Delete all the folders under 14.0

3. Try the installation again

Explanation

For the SharePoint Server

Explanation

SP_Services is a domain account used for the Service Applications Pools.  ex: When you create a Managed Metadata Service application and create a pool for it, you select this account!

SP_Crawl is used within the Search Service Application  to crawl content. The Search Service Application will automatically grant this account read access on all Web Applications. It will also run the SharePoint Windows Search Service.

SP_UserProfiles is the account used for the User Profile Synchronization between your Service Application and your Active Directory. This account does not need any local rights, however you need to give it Replicate Directory Changes rights on the Active Directory in order to allow the synchronization

Medium Security Option (Sweet Spot)

SUMMARY

For the SQL Server

Explanation

For the SharePoint Server

Explanation

In the Medium Security option we increase the security by adding two new accounts: The SP_Admin and the SP_Search. Instead of giving all the Farm Administration power to the SP_Farm account, the SP_Admin will be the one that installs and configures SharePoint 2013 and have the local administrator rights, while the SP_Farm will only run the services and connect to the database. Furthermore, instead of letting the SP_Crawl account run both the Windows Service and have FULL-READ rights on all the web applications, the SP_Search will now run the Windows Service. Here is the breakdown of the accounts:

SP_Farm is a domain account that the SharePoint Timer service and the web application for Central Administration use to access the SharePoint content database. This account does not need to be a local administrator. The SharePoint configuration wizard grants the proper minimal privilege in the back-end SQL Server database.The minimum SQL Server privilege configuration is membership in the roles securityadmin and dbcreator.

SP_admin is a domain account you use to install and configure the farm. It is the account used to run the SharePoint Configuration Wizard  for SharePoint 2013.The SPAdmin account is the only account that requires local Administrator rights. To configure the SPAdmin account in a minimum privilege scenario, it should be a member of the roles securityadmin and dbcreator on the SQL server.

SP_Services is a domain account used for the Service Applications Pools.  ex: When you create a Managed Metadata Service application and create a pool for it, you select this account!

SP_Crawl is used within the Search Service Application  to crawl content. The Search Service Application will automatically grant this account read access on all Web Applications.

SP_Search Is used to run the SharePoint Windows Search Service.

SP_UserProfiles is the account used for the User Profile Synchronization between your Service Application and your Active Directory. This account does not need any local rights, however you need to give it Replicate Directory Changes rights on the Active Directory in order to allow the synchronization.

High Security Option

SUMMARY

For the SQL Server

Explanation

The difference between the Medium Security and High Security Option is that we now have a separate account for each of the two base services: SQL_Agent and Database Engine.  Nothing changes for the SQL_Admin

For the SharePoint Server

Explanation

The only difference between the Medium security and the High Security option is that we now have a separate account for the Web Application Pool hosting the ‘My Sites’  since it has a different security policy than the other Web Applications .  I will only give the details for the new account in the breakdown:

SP_MySitePool  is a domain account used for the My Sites Web Application Pool Identity. It’s very similar to the SP_Pool, however it is only used for the My Sites Web Application.

Source: http://www.absolute-sharepoint.com/2013/01/sharepoint-2013-service-accounts-best.html
You can download all the information here in PDF format on  here: http://sdrv.ms/U6hvuU

Can I upgrade from Office SharePoint Server 2007 to SharePoint Server 2013?

Not directly, but you can do what we call a “double-hop” database attach to upgrade from Office SharePoint Server 2007 to SharePoint Server 2010, and then from SharePoint Server 2010 to SharePoint Server 2013. Back up your content databases from 2007, set up a small, temporary farm with SharePoint 2010 (you can even use virtual servers if you don’t have space, and a trial version), and attach and upgrade them to 2010 there. Then, set up your destination 2013 farm, back up the 2010 databases, and attach and upgrade them to SharePoint 2013.

This upgrade path also applies to upgrading from Windows SharePoint Services 3.0 to SharePoint Foundation 2013 – you must upgrade to SharePoint Foundation 2010 before you go to SharePoint Foundation 2013.

I don’t have an article about this “double-hop” upgrade path just yet, but I am working on getting one out there as soon as I can.

Source: http://blogs.technet.com/b/tothesharepoint/archive/2012/11/19/upgrade-frequent-questions-from-sharepoint-conference-2012.aspx

This model explains the process that you use when you upgrade from SharePoint Foundation 2010 or SharePoint Server 2010 to SharePoint Foundation 2013 or SharePoint Server 2013.

http://www.microsoft.com/en-us/download/details.aspx?id=30371

Source: http://www.fiechter.eu/blog/Lists/Posts/Post.aspx?ID=27&mobile=0
By Adrian Fiechter

The new global navigation in SharePoint 2013 looks very promising, anyway I assume that many persons out there want to change it. Especially the “SharePoint” title.

There are different approachs which can be considered to change the global navigation. For example, changing the Mastpages, using the newly introduced Design Packages or doing some dirty java script hacks. All of them are giving an impression as this is a complete overkill for such a small issue. The good news, it is.

Before the script:

After the script:

Microsoft has actually added a new property to the web application which allows us to replace the SharePoint text with custom HTML by PowerShell or object model.

With the following script you can change it and add your custom HTML there:

$app = Get-SPWebApplication -Identity https://www.fiechter.eu

$app.SuiteBarBrandingElementHtml = “<div class=’ms-core-brandingText’>AdriansPoint</div>”

$app.Update()

Source: http://www.fiechter.eu/blog/Lists/Posts/Post.aspx?ID=27&mobile=0
By Adrian Fiechter

How to setup Google Analytics for SharePoint 2013? Excellent article by  Adrian Fiechter explain how it can be done
Source Link: http://www.fiechter.eu/blog/Lists/Posts/Post.aspx?ID=34&mobile=0

nstallation:

1. Open your SharePoint 2013 site collection or your public website
2. Rename the URL in the browser (Login as needed with a site collection administrator / your admin account):

   Current URL: http://www.fiechter.eu/about-us

   Rename to: http://www.fiechter.eu/_catalogs/solutions

   Note: Somehow Microsoft has removed the possibility to show the sandbox solutions folder from the UI in public websites. Anyway as they are using it for design packages and website templates, I assume there will be no difficulties with no-code sandbox solutions.

3. Select Upload Solution

   

4. Select Browse… 

   

5. Download the solution package, extract it and upload the wsp file:http://www.fiechter.eu/blog/Solutions/Wsp365.GoogleAnalytics.zip

   

6. Click Open and OK to upload the solution.

    

7. Select Activate to install the solution.

   

8. Now, verify the activation was successfully 
9. Finally you have to add your Google Analytics code. For that you can open Site Settings:

   

10. There is a new menu entry point under Site Collection Administration which is called Google Analytics

    

     

11. Paste the google analytics code into the red square and press OK. That’s it.

To test if it works as expected, just open the website in a different browser and take a look on the html source. If your Google Analytics code is there, then everything is fine.

If you are unhappy with the solution, then just deactivate the sandbox solution over the same URL. As there is no modification on existing sites done, your site will work as before.

How to setup Google Analytics for SharePoint 2013? Excellent article by  Adrian Fiechter explain how it can be done
Source Link: http://www.fiechter.eu/blog/Lists/Posts/Post.aspx?ID=34&mobile=0