Reset Bios / CMOS battery

Hi Guys,

Get a blank screen on the first reboot after disabling the secure boot following the procedure in this link :-

http://h20565.www2.hp.com/portal/site/hpsc/template.PAGE/public/kb/docDisplay/?sp4ts.oid=5295884&spf_p.tpst=kbDocDisplay&spf_p.prp_kbDocDisplay=wsrp-navigationalState%3DdocId%253Demr_na-c03653226-8%257CdocLocale%253D%257CcalledBy%253D&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken

Laptop is

Product- F5Y33UA#ABA

Model - 15-d017d

(Thats all the info on the back, no product line eg... pavillion, envy, etc)

Tried a hard reset but no joy. Looking at some other posts on this forum, it seems that the next logical step would be to reset the CMOS. Trouble is I can't find any documentation to do with this laptop anywhere, so am unsure of the procedure. If somebody can point me in the right direction of a maintanence guide / user manual it would be very much appreciated.

Cheers