[Sprint HTC One (M8)] Erbat:
[MENTION=4779986]EVOuser94[/MENTION] I did the things you say ( [MENTION=7227115]Erbat[/MENTION] open a command prompt on your desktop without phone connection or anything and just simply type fastboot in it, and tell me results as well. This is me checking to see if you do in fact have the fastboot command linked to System environment Variables.

While you're at it simply type adb too.

Please post full command output in a code block [*code]Like this without the *'s[*/code])

And this is the results

(also unistall the HTC Sync and restart the whole PC like Kodec.4 says)

*Also a suggestion and option maybe I would try in other computer if it's necesary

C:\Users\Usuario\adb>fastboot
usage: fastboot [ <option> ] <command>

commands:
update <filename> reflash device from update.zip
flashall flash boot, system, vendor and if found,
recovery
flash <partition> [ <filename> ] write a file to a flash partition
flashing lock locks the device. Prevents flashing partitions
flashing unlock unlocks the device. Allows user to flash any partition except the ones that are related to bootloader
flashing lock_critical Prevents flashing bootloader related partitions
flashing unlock_critical Enables flashing bootloader related partitions
flashing get_unlock_ability Queries bootloader to see if the device is unlocked
erase <partition> erase a flash partition
format[:[<fs type>][:[<size>]] <partition> format a flash partition.
Can override the fs type and/or
size the bootloader reports.
getvar <variable> display a bootloader variable
boot <kernel> [ <ramdisk> ] download and boot kernel
flash:raw boot <kernel> [ <ramdisk> ] create bootimage and flash it
devices list all connected devices
continue continue with autoboot
reboot [bootloader] reboot device, optionally into bootloader
reboot-bootloader reboot device into bootloader
help show this help message

options:
-w erase userdata and cache (and format
if supported by partition type)
-u do not first erase partition before
formatting
-s <specific device> specify device serial number
or path to device port
-l with "devices", lists device paths
-p <product> specify product name
-c <cmdline> override kernel commandline
-i <vendor id> specify a custom USB vendor id
-b <base_addr> specify a custom kernel base address.
default: 0x10000000
-n <page size> specify the nand page size.
default: 2048
-S <size>[K|M|G] automatically sparse files greater
than size. 0 to disable

C:\Users\Usuario\adb>adb
Android Debug Bridge version 1.0.32
Revision eac51f2bb6a8-android

-a - directs adb to listen on all interfaces for a connection
-d - directs command to the only connected USB device
returns an error if more than one USB device is present.
-e - directs command to the only running emulator.
returns an error if more than one emulator is running.
-s <specific device> - directs command to the device or emulator with the given
serial number or qualifier. Overrides ANDROID_SERIAL
environment variable.
-p <product name or path> - simple product name like 'sooner', or
a relative/absolute path to a product
out directory like 'out/target/product/sooner'.
If -p is not specified, the ANDROID_PRODUCT_OUT
environment variable is used, which must
be an absolute path.
-H - Name of adb server host (default: localhost)
-P - Port of adb server (default: 5037)
devices [-l] - list all connected devices
('-l' will also list device qualifiers)
connect <host>[:<port>] - connect to a device via TCP/IP
Port 5555 is used by default if no port number is specified.
disconnect [<host>[:<port>]] - disconnect from a TCP/IP device.
Port 5555 is used by default if no port number is specified.
Using this command with no additional arguments
will disconnect from all connected TCP/IP devices.

device commands:
adb push [-p] <local> <remote>
- copy file/dir to device
('-p' to display the transfer progress)
adb pull [-p] [-a] <remote> [<local>]
- copy file/dir from device
('-p' to display the transfer progress)
('-a' means copy timestamp and mode)
adb sync [ <directory> ] - copy host->device only if changed
(-l means list but don't copy)
(see 'adb help all')
adb shell - run remote shell interactively
adb shell <command> - run remote shell command
adb emu <command> - run emulator console command
adb logcat [ <filter-spec> ] - View device log
adb forward --list - list all forward socket connections.
the format is a list of lines with the following format:
<serial> " " <local> " " <remote> "\n"
adb forward <local> <remote> - forward socket connections
forward specs are one of:
tcp:<port>
localabstract:<unix domain socket name>
localreserved:<unix domain socket name>
localfilesystem:<unix domain socket name>
dev:<character device name>
jdwp:<process pid> (remote only)
adb forward --no-rebind <local> <remote>
- same as 'adb forward <local> <remote>' but fails
if <local> is already forwarded
adb forward --remove <local> - remove a specific forward socket connection
adb forward --remove-all - remove all forward socket connections
adb reverse --list - list all reverse socket connections from device
adb reverse <remote> <local> - reverse socket connections
reverse specs are one of:
tcp:<port>
localabstract:<unix domain socket name>
localreserved:<unix domain socket name>
localfilesystem:<unix domain socket name>
adb reverse --norebind <remote> <local>
- same as 'adb reverse <remote> <local>' but fails
if <remote> is already reversed.
adb reverse --remove <remote>
- remove a specific reversed socket connection
adb reverse --remove-all - remove all reversed socket connections from device
adb jdwp - list PIDs of processes hosting a JDWP transport
adb install [-lrtsdg] <file>
- push this package file to the device and install it
(-l: forward lock application)
(-r: replace existing application)
(-t: allow test packages)
(-s: install application on sdcard)
(-d: allow version code downgrade)
(-g: grant all runtime permissions)
adb install-multiple [-lrtsdpg] <file...>
- push this package file to the device and install it
(-l: forward lock application)
(-r: replace existing application)
(-t: allow test packages)
(-s: install application on sdcard)
(-d: allow version code downgrade)
(-p: partial application install)
(-g: grant all runtime permissions)
adb uninstall [-k] <package> - remove this app package from the device
('-k' means keep the data and cache directories)
adb bugreport - return all information from the device
that should be included in a bug report.

adb backup [-f <file>] [-apk|-noapk] [-obb|-noobb] [-shared|-noshared] [-all] [-system|-nosystem] [<packages...>]
- write an archive of the device's data to <file>.
If no -f option is supplied then the data is written
to "backup.ab" in the current directory.
(-apk|-noapk enable/disable backup of the .apks themselves
in the archive; the default is noapk.)
(-obb|-noobb enable/disable backup of any installed apk expansion
(aka .obb) files associated with each application; the default
is noobb.)
(-shared|-noshared enable/disable backup of the device's
shared storage / SD card contents; the default is noshared.)
(-all means to back up all installed applications)
(-system|-nosystem toggles whether -all automatically includes
system applications; the default is to include system apps)
(<packages...> is the list of applications to be backed up. If
the -all or -shared flags are passed, then the package
list is optional. Applications explicitly given on the
command line will be included even if -nosystem would
ordinarily cause them to be omitted.)

adb restore <file> - restore device contents from the <file> backup archive

adb disable-verity - disable dm-verity checking on USERDEBUG builds
adb enable-verity - re-enable dm-verity checking on USERDEBUG builds
adb keygen <file> - generate adb public/private key. The private key is stored in <file>,
and the public key is stored in <file>.pub. Any existing files
are overwritten.
adb help - show this help message
adb version - show version num

scripting:
adb wait-for-device - block until device is online
adb start-server - ensure that there is a server running
adb kill-server - kill the server if it is running
adb get-state - prints: offline | bootloader | device
adb get-serialno - prints: <serial-number>
adb get-devpath - prints: <device-path>
adb remount - remounts the /system, /vendor (if present) and /oem (if present) partitions on the device read-write
adb reboot [bootloader|recovery]
- reboots the device, optionally into the bootloader or recovery program.
adb reboot sideload - reboots the device into the sideload mode in recovery program (adb root required).
adb reboot sideload-auto-reboot
- reboots into the sideload mode, then reboots automatically after the sideload regardless of the result.
adb reboot-bootloader - reboots the device into the bootloader
adb root - restarts the adbd daemon with root permissions
adb unroot - restarts the adbd daemon without root permissions
adb usb - restarts the adbd daemon listening on USB
adb tcpip <port> - restarts the adbd daemon listening on TCP on the specified port
networking:
adb ppp <tty> [parameters] - Run PPP over USB.
Note: you should not automatically start a PPP connection.
<tty> refers to the tty for PPP stream. Eg. dev:/dev/omap_csmi_tty1
[parameters] - Eg. defaultroute debug dump local notty usepeerdns

adb sync notes: adb sync [ <directory> ]
<localdir> can be interpreted in several ways:

- If <directory> is not specified, /system, /vendor (if present), /oem (if present) and /data partitions will be updated.

- If it is "system", "vendor", "oem" or "data", only the corresponding partition
is updated.

environmental variables:
ADB_TRACE - Print debug information. A comma separated list of the following values
1 or all, adb, sockets, packets, rwx, usb, sync, sysdeps, transport, jdwp
ANDROID_SERIAL - The serial number to connect to. -s takes priority over this if given.
ANDROID_LOG_TAGS - When used with the logcat option, only these debug tags are printed.