# "invalid partition table" trying to install Win7 from USB



## MikeHoward (Jan 15, 2014)

I have Win 7 on a USB stick. I used this same USB to install Win 7 on my laptop earlier today, install went smooth as silk.

Then put the same USB in my desktop (Dell Dimension e521), change the boot sequence to boot from the USB first, and i get black screen with error message "invalid partition table".

I then disabled all the hard drives and cd rom, and plug in the USB and boot, and i don't get that error, just a blank screen with blinking cursor top left. no movement for an hour now.

Any thoughts guys?

Windows 7 should be on this drive ok, if it installs properly on another computer right? Or might my desktop need the USB to be formatted differently?

Stuck,
Mike


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## DaveBurnett (Nov 11, 2002)

I would say that the machine Dell is not recognising the USB stick or will not boot from it. Try one of the rear USB ports.


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## MikeHoward (Jan 15, 2014)

DaveBurnett said:


> I would say that the machine Dell is not recognising the USB stick or will not boot from it. Try one of the rear USB ports.


Dave, thanks for the reply. I tried the USB stick in the back of the computer, same message.
I also tried the DiskPart utility to format the USB again in hopes it would fix this error.

What else would you suggest/like me to try to get to the bottom of this.

FYI, I do not have a way to burn this to a disk, so i am hoping to get it working off the USB.

Mike


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## DaveBurnett (Nov 11, 2002)

Just confirm 2 things.
You did *boot* from the USB and install from it earlier?
Your desktop WILL boot from USB and you have checked this by doing so on another occasion with a different USB.

It would also be useful to check that the desktop will boot from an identical USB stick with anything on it.


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## MikeHoward (Jan 15, 2014)

DaveBurnett said:


> Just confirm 2 things.
> You did *boot* from the USB and install from it earlier?
> Your desktop WILL boot from USB and you have checked this by doing so on another occasion with a different USB.
> 
> It would also be useful to check that the desktop will boot from an identical USB stick with anything on it.


Dave,

#1. I did boot from this exact USB (with same Win7 files on it) and re-installed the OS on my laptop two hours ago. Trying to boot from it on Desktop proving problamatic

#2. My desktop will read from this USB, when i allow it to boot its current version of windows. Not sure how to test if it will boot "from" this USB, other than with the OS i have on there. What should i put on there to test this USB?

#3. I have two seperate USB sticks with the Win7 on them (both have worked on other computers) and both throw the same error when trying to boot the desktop from either USB stick (front and back USB slots)


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## DaveBurnett (Nov 11, 2002)

Booting from USB is very much hit and miss. I have dozens of makes of USB sticks here and several makes of machine. Some sticks will boot on one machine and not on another. Other sticks work the opposite. Some work with all; some with none. Even those that do boot can behave differently. Some behave like hard drives, some behave like superfloppy drives and some will do both.

When you press F12 on boot to bring up the boot device list does the USB stick show on it. It should do!


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## MikeHoward (Jan 15, 2014)

when i press F12 it shows:
*Normal
+ * Bootable Hard Drive
* USB-ZIP (when i boot without my USB plugged in the front slot, this USB-ZIP does NOT show up in the options after F12)

so yes, it does show up. i hit the down arrow down to that drive, then enter, and it throws this "Invalid Partition Table" error. tried two USBs so far, and that's all i have with me that can fit Win7


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## DaveBurnett (Nov 11, 2002)

So it is showing as a superfloppy. 
If you have a copy of the data on there, or it is easily replaceable, see if computer management or a partition tool will let you partition it with more that one partition.


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## MikeHoward (Jan 15, 2014)

Dave.....i took your suggestion about different USBs, went to my neighbor and borrowed to 8GBs USB drives from him....reformatted both and one of them worked.

Woooohoooo.....thanks so much for your help! so weird!


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