Hello,
The CRSAdministrator is a local user in the UCCX server that is used to run the main UCCX services.
You cannot change this password from Computer Management, you'll need to use the Admin Utility. The Administration Guide will give you additional information on page 315 - UCCX Admin Utility:
www.cisco.com/en/US/docs/voice_ip_comm/cust_contact/contact_center/crs/express_7_0/configuration/guide/uccx70ag.pdf
The process of changing the CRSAdministrator from Admin Utility will reboot the CRS Node Manager, so process is service affecting, hence it must be run after business hours.
After the password is changed and the Node Manager restarted, please go to the Programs> Administrative Tools> Services window and make sure the 4 services running under the .\CRSAdministrator account have started: Cisco Desktop Recording Service, Cisco Unified CCX Node Manager, MSSQL$CRSSQL, and SQLAgent$CRSSQL.
For the ASPNET, honestly I'm not quite sure, but I would recommend NOT changing this password. The UCCX installer installs Microsoft .NET Framework. MS .NET installer will create the ASPNET user and certain folders will have ASPNET added as permissible user. I believe that if you change this password, it will might break the web service/application.
HTH
Pablo