I haven't updated my Windows recently atleast. The version I was using until I upgraded was "Version 1.0 revision 3164 (2006-11-01 12:09:43) gcc 3.4.5 Windows/unicode" and I didn't have any problems with that one. I tried Settings -> Editor -> Code-completion and symbols browser -> [X] Disable code-completion. That didn't work atleast, maybe you meant disabling it some other way? ^^
edit: When I removed "[ ] Check & set file associations (Windows only)", and deleted the ddeexec keys from the registry CB stopped complaining about being unable to open keys atleast. Only problem is I get lots of Code::Blocks instances now instead of just one, but I'll probably get used to it ^^
edit2: Seems like it only freezes if there are no Code::Blocks currently running, so I'll just launch Code::Blocks first and then open files from explorer.exe as usual. I tried packing the files in winrar etc too, just to see if it only was explorer.exe freezing, but winrar.exe froze too.