moving from express 2005 to express R2 2008

[icarium]

Hello,
I have a website (in development) with sql express 2005 db, and I want to upgrade to express R2 2008 version (mainly because of 10gb vs 4gb max db size), how do I do that?, I have win xp os do I need to upgrade to win7? Also I have VS 2005 is that prohibitive to using the R2 2008?
I've red somewhere that you can have the two versions on the same machine, is that true?

Thanks for your response.

[finito]

Back up restore

[sknake]

You can run mixed versions of SQL to a certain extend but I would not recommend it, unless unavoidable.

Download the appropriate installer:
x64 - SQLEXPRWT_x64_ENU.exe
x86 - SQLEXPRWT_x86_ENU.exe

Make sure you have installed the pre-requisits:
.NET Framework 3.5 SP1

Windows 7
•Windows Powershell 1.0 - Included with OS
•Windows Installer 5.0 - Included with OS
•Internet Explorer 6 SP1 or later - Included with OS
Windows Server 2003
•Windows Powershell 1.0 - x86 x64
•Windows Installer 4.5 - x86 x64
•Windows Installer 4.5 Update - x86 x64
•Internet Explorer 6 SP1 or later - Included with OS
Windows Server 2008
•Windows Powershell 1.0 - C:\> servermanagercmd -install powershell
•Windows Installer 4.5 - x86 x64
•Internet Explorer 6 SP1 or later - Included with OS
Windows Vista
•Windows Powershell 1.0 - x86 x64
•Windows Installer 4.5 - x86 x64
•Internet Explorer 6 SP1 or later - Included with OS
Windows XP
•Windows Powershell 1.0 - x86
•Windows Installer 4.5 - x86
•Windows Installer 4.5 Update - x86
•Internet Explorer 6 SP1 or later

Here are the installation parameters I use. They may not fit your needs exactly but it should help you on your way:
Unattended Installation:

/ACTION=Install /qs /SkipRules=RebootRequiredCheck /FEATURES=SQL,TOOLS /INSTANCENAME=InstanceName /SQLSVCACCOUNT="NT AUTHORITY\Network Service" /SQLSVCStartupType=Automatic /RSSVCACCOUNT="NT AUTHORITY\Network Service" /RSSVCStartupType=Automatic /ADDCURRENTUSERASSQLADMIN="True" /ENABLERANU=0 /ERRORREPORTING="True" /SQMREPORTING="True" /SECURITYMODE="SQL" /TCPENABLED="1" /NPENABLED="1" /BROWSERSVCSTARTUPTYPE="Automatic" /INSTALLSHAREDDIR="%ProgramFiles%\Microsoft SQL Server" /INSTANCEDIR="%ProgramFiles%\Microsoft SQL Server" /SAPWD="Password" /SQLSYSADMINACCOUNTS="BUILTIN\ADMINISTRATORS" /IACCEPTSQLSERVERLICENSETERMS

Attended Installation:

/ACTION=Install /UIMODE=AutoAdvance /SkipRules=RebootRequiredCheck /FEATURES=SQL,TOOLS /INSTANCENAME=InstanceName /SQLSVCACCOUNT="NT AUTHORITY\Network Service" /SQLSVCStartupType=Automatic /RSSVCACCOUNT="NT AUTHORITY\Network Service" /RSSVCStartupType=Automatic /ADDCURRENTUSERASSQLADMIN="True" /ENABLERANU=0 /ERRORREPORTING="True" /SQMREPORTING="True" /SECURITYMODE="SQL" /TCPENABLED="1" /NPENABLED="1" /BROWSERSVCSTARTUPTYPE="Automatic" /INSTALLSHAREDDIR="%ProgramFiles%\Microsoft SQL Server" /INSTANCEDIR="%ProgramFiles%\Microsoft SQL Server" /SAPWD="Password" /SQLSYSADMINACCOUNTS="BUILTIN\ADMINISTRATORS" /IACCEPTSQLSERVERLICENSETERMS

Other resources:
How to: Install SQL Server 2008 R2 from the Command Prompt
Enabling remote connections
How to install SQL Server 2008 R2