I have a colleague who is setting up a test farm. He installed SP 2013 on the server, then decided he didn't want 2013 and then uninstalled 2013, then installed SP 2010. My understanding was that this is a big no no. If you have to reinstall SP, you might as well start with a clean server. Especially if you had a different version of SP. However, I can't find any concrete documentation from MS on this or whether it is supported or not. Does anybody have an opinion on this with link to MS's official position on this?
i would go with the clean installation, rebuild the server.
- SharePoint 2010 build on .Net 3.5 SP1 and does not support .net 4.0 or higher while on other hand SP2013 required .net 4.5,
- there are many new pre requisite which required for SharePoint 2013(should be installed during the installation process) which are not compatible with SP2010.
- Once you uninstall the SharePoint 2013 still left over on the server which cause the issue with your SP2010. You are coming from New version to old.
I strongly recommend rebuild the server, otherwise clean up properly( uninstall everything, pre-requisite.).
What version of server you are using, Windows 2008 or 2012?