How to add a DSRM startup option in Windows Server 2008 R2

From this blog post we should open an administrator command prompt and enter these lines:
bcdedit /copy {current} /d "Directory Services Restore Mode"
bcdedit /set {GUID} safeboot dsrepair
bcdedit /timeout 10
where {GUID} is the result of the first command.

How to find the exact version of my Exchange 2010

From a powershell console enter this command:
Get-Exchangeserver -Identity
If you want to know the exact version then enter this command:
gcm exsetup |%{$_.Fileversioninfo}
For more info take a look at this article from Technet.

How to update ESXi 5 using esxcli

Please read the following article from VMware.

Exchange Management Console cannot close after installation of IE9

This is a quick fix: You must turn off Internet Explorer Enhanced Security Configuration using "Manage My Computer", add https://localhost to the IE9 trusted sites and reboot.

How to enable SAN certificates in a Windows 2008 R2 Enterprise CA

Open a command prompt windows and enter these commands:
certutil –setreg policy\SubjectAltName enabled
certutil –setreg policy\SubjectAltName2 enabled
net stop certsvc
net start certsvc
Now you can submit your exchange SAN certificate request using this command line:
certreq -submit -attrib "CertificateTemplate:WebServer" c:\tmp\excertreq.req excert.cer
where excertreq.req is the request file and excert.cer is the issued certificate.
In case of error you must convert the .req file to ANSI format from Unicode using notepad.
For more info read Windows 2008 PKI / Certificate Authority (AD CS) basics and How to issue EV SSL certificates from an Enterprise CA

Troubleshooting "The RPC server is unavailable"

Please read the following article from Microsoft Technet Wiki

How to disable EDNS probes in Windows Server 2008 R2 DNS server

Open a command line and enter this command
dnscmd /config /EnableEDNSProbes 0
You don't have to reboot the server.

How to find my exchange server schema version

From a domain controller open a command prompt and enter this command
dsquery * CN=ms-Exch-Schema-Version-Pt,cn=schema,cn=configuration,dc=yourdomainname,dc=local -scope base -attr rangeUpper
where yourdomainname is your domain name.
For more information read the following article Exchange Schema Versions - Common Questions & Answers

Exchange server schema versions

Schema Version	rangeUpper Value
Exchange 2003 RTM	6870
Exchange 2003 SP1	6870
Exchange 2003 SP2	6870
Exchange 2007 RTM	10637
Exchange 2007 SP1	11116
Exchange 2007 SP2	14622
Exchange 2007 SP3	14625
Exchange 2010 RTM	14622
Exchange 2010 SP1	14726

How to enumerate the list of installed hotfixes in Windows using WMI

From a command line enter the following command:
wmic qfe list full /format:htable > C:\tmp\hotfixes.htm
You can open the file htofixes.htm using your browser.