Remove bad dll reference after content data migration sharepoint 2007 - sharepoint 2010

Question

I have 400 subsites under one root site and we need to remove one DLL reference from default.aspx Home page of each sub site.
Assmbly ref like this.
<%@ Register TagPrefix="WpNs0" Namespace="DS.DSQueryWebPart" Assembly="DS.DSQueryWebPart, Version=1.0.0.0, Culture=neutral, PublicKeyToken=709ed70a96eaa5cb"%>
This assmebly is not used anywhere .
This assembly is reflecting in subsite default.aspx after the content database migration sharepoint 2007 to sharepoint 2010.
Is there any way we can remove this bad reference through database query or any other way around
sarav

Answer 1

Hi,
If are sure that this is the only customization in the default.aspx page, then you can safely  go into Site Settings -> Site Actions -> Reset to site definition -> Select Reset specific page to site definition version and enter the default.aspx
page url. This will replace the customized page with the original site definition page. The process can be automated using PowerShell/C# Code. Here is an example:
using (SPSite site = new SPSite("http://aissp2013/sites/Team/"))
   foreach(SPWeb web in site.AllWebs)
  using(web)
  SPFile file = web.GetFile(web.Url + "/default.aspx");
  if (file.Exists)
  file.RevertContentStream();
The main part here is to get hold of the default.aspx file and use RevertContentStream() to reset it to site definition page.
However, if there are other customizations as well, then you will need to get hold of the Project or WSP file and remove the reference there and then run update-spsolution powershell command to update to new WSP.
Thanks,
Nadeem
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