HELP compaq CQ45-805TU Recovery ISO

Please someone help me from my nightmare of working on this compaq notebook, with dvd.
My daughterin-law's computer Compaq CQ45-805TU Win 8 it was running rough so she asked if I could have a look I said yep (wish I didnt) cleaned it out hadnt been done since she had it, all went well, re started all working fine. Then she asked if I could put in the update that kept popping up I said yes, update was to go from win8 to win8.1 all went well I thouht, next day started it on my way to make a coffee. Nothing! Black screen. So I left it for awhile it said there was a problem and it was trying to repair it. Over and over again. So stopped it let it boot up same thing only the logo splashed up for a second said attempting repair then just black screen. Then after a few mins un happy face comes up said there was a problem. I have done the f2. Nothing in there to help did a memory scan and hard drive scan. Came up with a software error.
Only chance is if I can find borrow beg steal a copy of an ISO of the recovery disk. I know you can buy the disks from HP but I or my Daughter-In-law just cant afford it.
can anyone suggest anything I can do.
Regards Brian