WRC 11.02.712 portable version, same computer, all items, (fast, safe or deep???) scan.
Scan started 07:58:10 PM - 19:58.10 (CEST - Italian time)
Scan aborted 08:19:30 PM - 20:19:30 (it was checking empty keys)
21 minutes and 20 seconds (1280 seconds) and the scan didn't finish...
WRC 8.83.563 portable version, same computer, all items, deep scan.
Scan started 20:20:10
Scan finished 20:21:19
248 problems found in 69 seconds.
WRC user guide refers to wise registry cleaner X, where fast and deep scan are available.