SQL SERVER 2005 - Installation SP4

Hi Expert!

We Installed SQL Server 2005 seven years back (In 2008/2009) but unfortunately  not install any service pack yet.

Following is SQL server information:

Microsoft SQL Server Management Studio9.00.4035.00
Microsoft Analysis Services Client Tools2005.090.4035.00
Microsoft Data Access Components (MDAC)2000.086.1830.00 (srv03_sp1_rtm.050324-1447)
Microsoft MSXML2.6 3.0 5.0 6.0 
Microsoft Internet Explorer6.0.3790.1830
Microsoft .NET Framework2.0.50727.1891
Operating System5.2.3790

 

My question is that if I installed directly SP4 now, so is there any risk on running business application.....

PS: SQL server 2005 installed on Windows 2003 64 bit

Thanks