I installed Windows 10 and now my imac wont boot and i cannot restore

Joined
Feb 16, 2015
Messages
6
Reaction score
0
Points
1
Yesterday i decided to try to install windows 10 via boot camp, everything was okay till windows was installed and the mac restarted. I have bootable usb flash drive with windows but when i try to install again there is no partition available. When i go to disk utility i dont see macintosh hd partition anymore, only "OS X Base System".
When usb flash is installed i have boot options - windows 10 and efi, but when i remove the usb mac does not load - folder with question mark flash.
Please advice what i can do now i dont want to open my mac as it has warranty.
Thanks in advance
 

Slydude

Well-known member
Staff member
Moderator
Joined
Nov 15, 2009
Messages
17,664
Reaction score
1,121
Points
113
Location
North Louisiana, USA
Your Mac's Specs
M1 MacMini 16 GB - Ventura, iPhone 14 Pro Max, 2015 iMac 16 GB Monterey
Are you getting to Disk Utility by accessing the recovery partition (pressing Command R at startup)? It sounds to me like you have accidentally deleted OS X from your drive. If that's the case you'll probably need to reinstall OS X though someone else may have other suggestions.

Do you have a backup (Time Machine or bootable clone)?
 
Joined
Jul 24, 2013
Messages
5,084
Reaction score
789
Points
113
Location
Ohio (USA)
Your Mac's Specs
2023-14" M3max MBPro, 64GB/1TB, iPhone 15 Pro, Watch Ultra
Yeah what Slydude ^^^ said. And don't open your mac!!! If you have erased the hard drive you can reinstall the OS. We can help you with that.

Lisa
 

chscag

Well-known member
Staff member
Admin
Joined
Jan 23, 2008
Messages
65,247
Reaction score
1,834
Points
113
Location
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
As the two previous replies have already stated, you very likely formatted your OS X partition as NTFS when you were setting up the Windows 10 Preview. Your only option now is to boot to your recovery partition (command + r) and remove the Windows partition. Then, reinstall Yosemite.
 
Joined
Feb 17, 2015
Messages
1
Reaction score
0
Points
1
yes i think i have erased the mac os and format the partition so it does not see it right now
in disk utility there is no hard drive only OS X Base System
please advice how to procede
 
OP
M
Joined
Feb 16, 2015
Messages
6
Reaction score
0
Points
1
when i go to internet recovery it asks to chose drive to install it, but the problem is my imac does not see the hard drive partition, otherwise its easy to reinstall
 
OP
M
Joined
Feb 16, 2015
Messages
6
Reaction score
0
Points
1
As the two previous replies have already stated, you very likely formatted your OS X partition as NTFS when you were setting up the Windows 10 Preview. Your only option now is to boot to your recovery partition (command + r) and remove the Windows partition. Then, reinstall Yosemite.

but how to remove the windows and reformat the hard drive to install mavericks, now my imac does not recognize the hard drive
 
Joined
Feb 14, 2004
Messages
4,781
Reaction score
166
Points
63
Location
Groves, Texas
What do you get when you startup holding down the Option key?
 
Joined
Jan 25, 2015
Messages
4
Reaction score
0
Points
1
Location
Thurso Scotland
Your Mac's Specs
5K imac
Hi
I have been where you are now having tried to install windows 10 and my Macintosh HD was no longer recognised as if it just didn't exist! Since you say you have a warranty on your Mac I strongly advise you to take it in for attention, believe me I am not scaremongering when I say this could cost you a new HDD if you don't take it in and even if you do this may turn out to be the only way back. To anyone tempted to try to install windows 10 DONT! it may just be too expensive
 

chscag

Well-known member
Staff member
Admin
Joined
Jan 23, 2008
Messages
65,247
Reaction score
1,834
Points
113
Location
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
The best way to install the Windows 10 public preview is to use virtualization. Since VirtualBox from Oracle is free and the 10 preview is likewise free, the only thing you can lose is some time and maybe your patience.... O:)
 
Joined
Jul 24, 2013
Messages
5,084
Reaction score
789
Points
113
Location
Ohio (USA)
Your Mac's Specs
2023-14" M3max MBPro, 64GB/1TB, iPhone 15 Pro, Watch Ultra
Yeah what ^^^^chscag said! I have been there and done that! I installed Virtual Box and then Windows 10. If you decide to go that route post back and I will give you some of my hard learned tips for how to do it with the least amount of hassle.

Lisa
 
OP
M
Joined
Feb 16, 2015
Messages
6
Reaction score
0
Points
1
so hard is gone ? how its possible i only format one of the partitions lol
will this be covered by apple warranty ?
 

chscag

Well-known member
Staff member
Admin
Joined
Jan 23, 2008
Messages
65,247
Reaction score
1,834
Points
113
Location
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
so hard is gone ? how its possible i only format one of the partitions lol
will this be covered by apple warranty ?

It's very easy to accidentally format your OS X partition if you're not careful during the setup process for Boot Camp. Anyway, we really don't know what happened. As for your warranty... if your machine is still under warranty, take it into an Apple Store and ask for assistance. They'll get you up and running. The only problem is that you will lose any data that you haven't backed up.
 
Joined
Dec 18, 2011
Messages
50
Reaction score
1
Points
8
Your Mac's Specs
MacBook Pro 9,2; 2.5 GHz Intel Core i5; 16 GB 1600 MHz DDR3
Yesterday i decided to try to install windows 10 via boot camp, everything was okay till windows was installed and the mac restarted. I have bootable usb flash drive with windows but when i try to install again there is no partition available. When i go to disk utility i dont see macintosh hd partition anymore, only "OS X Base System".
When usb flash is installed i have boot options - windows 10 and efi, but when i remove the usb mac does not load - folder with question mark flash.
Please advice what i can do now i dont want to open my mac as it has warranty.
Thanks in advance

I would only add to the excellent advice given already that you haven't once mentioned your method of data backup as a resource from which to undo what has occurred. If that means you have not been continuously backing up (at least your data but preferably your entire internal disk) with Time Machine, SuperDuper, Carbon Copy Cloner or some equally good method, please take this experience to heart as a hard lesson never to be repeated. Murphy's Law applies to everyone. Using a computer without a sound backup method in place is extremely reckless. Once you are again up and running, please make a reliable backup method part of your ongoing use of your computer.

Best wishes, Nate :D
 
OP
M
Joined
Feb 16, 2015
Messages
6
Reaction score
0
Points
1
i had no important information on the computer i just wanted to try it with windows i never thought things will mess like that, on windows PC there is nothing you can do that cant be repaired. however i send it for repair i will see whats gonna happen this should be easy work for apple technicians
 
Joined
Dec 18, 2011
Messages
50
Reaction score
1
Points
8
Your Mac's Specs
MacBook Pro 9,2; 2.5 GHz Intel Core i5; 16 GB 1600 MHz DDR3
i had no important information on the computer i just wanted to try it with windows i never thought things will mess like that, on windows PC there is nothing you can do that cant be repaired. however i send it for repair i will see whats gonna happen this should be easy work for apple technicians

As a user of both Windows PCs and Macs for decades and decades, I strongly disagree with that statement! The facts IMHO are just the opposite.

Regards, Nate :D
 
OP
M
Joined
Feb 16, 2015
Messages
6
Reaction score
0
Points
1
i am using windows for about 10 years and i have never experienced such a problem, i mean to format one partition and the whole hard disk vanished, operating system gone too and there is nothing you can do about it, thats not normal... in windows its pretty easy - format and install problem fixed
and the funny part is the problem came up from a program that comes from apple boot camp, for which they do not offer technical support omg
 
Joined
Feb 12, 2015
Messages
17
Reaction score
0
Points
1
Your Mac's Specs
27 in iMac late 2013. i5 4570/ 8GB/ 1 TB
i am using windows for about 10 years and i have never experienced such a problem, i mean to format one partition and the whole hard disk vanished, operating system gone too and there is nothing you can do about it, thats not normal... in windows its pretty easy - format and install problem fixed
and the funny part is the problem came up from a program that comes from apple boot camp, for which they do not offer technical support omg

Then I suggest you go run Mac OS X on Windows with the Microsoft provided tools? Wait, you can'y because they don't.

I have been using a Microsoft OS since about 1985-85 and there are many, many, many problems that Windows can decide to just up and have out of the blue.

You have used Windows for about 10 years, okay. How long you been using a Mac? I did the exact same thing you did with Windows 7. I erased Mac OS and that was user error, nothing I should hold Apple accountable for at all. Then I went and realized and asked myself why I was inclined to go back to an OS that has given me many problems for many years. Why? The Apple computer I have right in front of me does most of what I have ever done on a machine, for what it don't I will seek alternatives.

Here is the point. May people use many different operating systems and the people who know how to use said system have few problems. To come on a Mac forum and accuse the system of being broken is just wrong.

Our old habits are what's broken, nothing wrong with the Mac.
 

Shop Amazon


Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
Top