I work with CRM ¾ and all the system works very slowly
Loading pages is very slow, and all the system looks busy.
One of the options is Antivirus.
When you work with CRM and open some pages for instance Edit.aspx not only the edit.aspx is downloaded from server many JavaScript + CSS + other linked pages is downloaded too
If antivirus is working check if Antivirus is scanning all the scripts and pages when you request page from CRM.
if yes... change the Antivirus to prevent of scanning all CRM pages and the performance back to be perfect
I got this problem with Antivirus MCAfee.
workaround
http://support.microsoft.com/kb/924341
https://kc.mcafee.com/corporate/index?page=content&id=KB65382&actp=search&viewlocale=en_US&searchid=1278011200919
Thanks,
Rami Heleg.