If there's a log in the stdoutdae.txt and stderrdae.txt files, post content.

Important is with Win8 that u install absolutely as a local user or as service [latter recommended with the option "Allow all users"]. Don't install under the MS online account... that risks to loose the BOINC data dir on each boot.

stderrdae.txt (core client error file) suggests quite clearly there's an attempt to start BOINC twice...

04-Feb-2015 23:04:17 Another instance of BOINC is running.
GLE:
05-Feb-2015 09:48:09 Another instance of BOINC is running.
GLE:
07-Feb-2015 22:09:08 Another instance of BOINC is running.
GLE:
08-Feb-2015 00:21:24 Another instance of BOINC is running.
GLE:
08-Feb-2015 00:32:37 Another instance of BOINC is running.
GLE:
11-Feb-2015 15:06:11 Another instance of BOINC is running.
GLE:
11-Feb-2015 15:46:03 Another instance of BOINC is running.
GLE:
11-Feb-2015 16:12:46 Another instance of BOINC is running.
GLE:
14-Feb-2015 08:57:21 Another instance of BOINC is running.
GLE:
15-Feb-2015 15:00:56 Another instance of BOINC is running.
GLE:
16-Feb-2015 15:11:44 Another instance of BOINC is running.
GLE:
18-Feb-2015 10:48:02 Another instance of BOINC is running.
GLE:
19-Feb-2015 13:50:28 Another instance of BOINC is running.
GLE:
21-Feb-2015 10:30:53 Another instance of BOINC is running.
GLE:
24-Feb-2015 12:52:51 Another instance of BOINC is running.
GLE:
24-Feb-2015 23:42:43 Another instance of BOINC is running.
GLE: 24-Feb-2015 23:42:43 Another instance of BOINC is running.
GLE: 24-Feb-2015 23:42:43 Another instance of BOINC is running.
GLE: 24-Feb-2015 23:42:
26-Feb-2015 22:42:00 Another instance of BOINC is running.
GLE: 26-Feb-2015 22:42:00 Another instance of BOINC is running.
GLE: 26-Feb-2015 22:42:00 Another instance of BOINC is running.
GLE: 26-Feb-2015 22:42:
02-Mar-2015 22:35:21 Another instance of BOINC is running.
GLE: 02-Mar-2015 22:35:21 Another instance of BOINC is running.
GLE: 02-Mar-2015 22:35:21 Another instance of BOINC is running.
GLE: 02-Mar-2015 22:35:
04-Mar-2015 15:28:45 Another instance of BOINC is running.
GLE: 04-Mar-2015 15:28:45 Another instance of BOINC is running.
GLE: 04-Mar-2015 15:28:45 Another instance of BOINC is running.
GLE: 04-Mar-2015 15:28:
05-Mar-2015 14:48:23 Another instance of BOINC is running.
GLE: 05-Mar-2015 14:48:23 Another instance of BOINC is running.
GLE: 05-Mar-2015 14:48:23 Another instance of BOINC is running.
GLE: 05-Mar-2015 14:48:
10-Mar-2015 14:28:19 Another instance of BOINC is running.
GLE: 10-Mar-2015 14:28:19 Another instance of BOINC is running.
GLE: 10-Mar-2015 14:28:19 Another instance of BOINC is running.
GLE: 10-Mar-2015 14:28:
11-Mar-2015 10:25:30 Another instance of BOINC is running.
GLE: 11-Mar-2015 10:25:30 Another instance of BOINC is running.
GLE: 11-Mar-2015 10:25:30 Another instance of BOINC is running.
GLE: 11-Mar-2015 10:25:
New Token ACL Success!!!

Do you remember what you did at 10:25 14:28 14:48 15:28 22:35 etc etc.

The stdoutdea.txt (core client output file) has a lot of the same but certainly tells there's no projects attached. There's though seemingly gridrepublic as account manager attached to the 7.2.47 client [suspect this is the WCG version]. The log also tells the client is installed under two different accounts

11-Mar-2015 11:03:18 [---] Running under account boinc_master

Which means, BOINC was installed as service

And

10-Mar-2015 14:28:10 [---] Running under account ÃéÜííçò-ÐçãÞ

Which is a user account [You?]

Suggest to uninstall everything BOINC, then go into the Programs & Features control panel and verify all BOINC is removed, no longer listed. Then boot and install 7.2.47 again, Service+Allow All Users. Do no add an account manager like Grid Republic, just follow the WCG instructions to add WCG with membername/password, same as logging into the website. This FAQ, chapter 4 shows screenshots of the install steps for the v7 client. http://www.worldcommunitygrid.org/forums/wcg/viewthread_thread,28971

Let us know what happened.

P.S. As noted in first reply, make sure to log in as a local user before installing, -not- with the MS account. This can result in your conflicting situation of both a service and a local user install being present. As service it will ensure that BOINC runs even if nobody is signed in... sort of you powering up and going for a coffee. When you come back to sign in, BOINC is already going. :O)

Hmmm, where did you get your BOINC installer from? For the one and only WCG code audited and partners endorsed version 7.2.47 go https://secure.worldcommunitygrid.org/reg/ms/viewDownloadAgain.do

Edit: To be sure you go clean installing, delete all and everything in C:\ProgramData\BOINC . There could/will be remnants there after an uninstall.