Your icon cache might be getting a bit bloated. Look for iconcache.db in C:\Documents and Settings\<user name>\Local Settings\Application Data, and delete it. You'll need to 'show hidden files' in order to get to it.
You can also disable the Indexing Service since its biggest 'feature' is slowing everything down.
You can also disable the Indexing Service since its biggest 'feature' is slowing everything down.