>>>>As a test we have upgraded a machine with SQL server 2008R2 to Windows 10 this morning.
>>>>
>>>>Prior to the upgrade SQL server performed fine. However after the upgrade especially table scan operations where one or two orders of magnitude slower.
>>>>
>>>>Any idea, what could be at play here? The specs of the machine are just fine intel I5, 3.1Ghz and 8 Gb of RAM. The task manager does not reveal anything stressing resources.
>>>>
>>>>Walter,
>>>
>>>SQL Server 2008 and SQL Server 2008 R2 are not supported by Windows 10. Check
>>>
>>>https://social.technet.microsoft.com/Forums/en-US/bb5f2199-f283-4249-a029-53978d637148/sql-service-stops-working-after-windows-10-upgrade?forum=sqldatabaseengine
>>>
>>>and the article referenced in that thread https://support.microsoft.com/en-us/kb/2681562
>>
>>Thanks for this, but I do not have any issues anymore with the SQL 2008R2 install. After a restart it seems to work fine. But I'll keep this in mind anyways.
>>
>>Walter,
>
>Hi Walter,
>
>I can't dare move to W10 yet, I just clicked yet and I'm in the wait list. How it's going?

AFAICS, it working fine. It looks like it is not always so snappy as Windows 8.1 was, but that might be due to the upgrade routine rather than a fresh install. But so far it seems stable.

Walter,