<s>
A	O
barebone	B-Device
computer	I-Device
is	O
a	O
partially	O
assembled	O
platform	O
or	O
an	O
unassembled	O
kit	O
of	O
computer	O
parts	O
allowing	O
more	O
customization	O
and	O
lower	O
costs	O
than	O
a	O
retail	O
computer	O
system	O
.	O
</s>
<s>
They	O
are	O
available	O
for	O
desktop	B-Device
computer	I-Device
,	O
notebook	O
(	O
see	O
barebook	B-Device
)	O
and	O
server	B-Application
purposes	O
,	O
and	O
in	O
nearly	O
any	O
form	O
factor	O
.	O
</s>
<s>
Manufacturers	O
are	O
also	O
able	O
to	O
produce	O
systems	O
of	O
a	O
specialized	O
or	O
non-standard	O
form	O
factor	O
,	O
since	O
the	O
system	O
is	O
sold	O
as	O
a	O
pre-built	O
unit	O
,	O
with	O
the	O
motherboard	B-Device
and	O
power	O
supply	O
already	O
installed	O
.	O
</s>
<s>
Assembling	O
a	O
barebone	B-Device
computer	I-Device
by	O
hand	O
is	O
usually	O
less	O
expensive	O
than	O
buying	O
a	O
pre-configured	O
computer	O
from	O
a	O
retailer	O
,	O
and	O
may	O
save	O
time	O
and	O
labor	O
compared	O
with	O
building	O
a	O
system	O
from	O
scratch	O
.	O
</s>
<s>
A	O
typical	O
barebone	O
desktop	B-General_Concept
system	I-General_Concept
consists	O
of	O
a	O
CPU	B-General_Concept
,	O
a	O
computer	B-General_Concept
case	I-General_Concept
(	O
or	O
tower	B-General_Concept
)	O
,	O
with	O
a	O
pre-fitted	O
motherboard	B-Device
and	O
power	O
supply	O
.	O
</s>
<s>
If	O
not	O
already	O
provided	O
,	O
the	O
purchaser	O
of	O
such	O
a	O
platform	O
only	O
has	O
to	O
equip	O
it	O
with	O
a	O
RAM	B-Architecture
,	O
and	O
optionally	O
a	O
hard	B-Device
drive	I-Device
(	O
in	O
some	O
cases	O
,	O
an	O
operating	B-General_Concept
system	I-General_Concept
is/can	O
be	O
installed	O
to	O
a	O
lower-cost	O
flash	O
drive	O
instead	O
)	O
.	O
</s>
<s>
Sometimes	O
,	O
it	O
is	O
necessary	O
to	O
install	O
an	O
operating	B-General_Concept
system	I-General_Concept
if	O
the	O
one	O
built	O
into	O
the	O
motherboard	B-Device
is	O
deemed	O
insufficient	O
(	O
or	O
not	O
present	O
at	O
all	O
)	O
.	O
</s>
<s>
An	O
audio	B-Device
adapter	I-Device
or	O
network	B-Protocol
adapter	I-Protocol
may	O
be	O
added	O
but	O
this	O
is	O
less	O
common	O
as	O
recent	O
motherboards	B-Device
often	O
already	O
contain	O
capable	O
solutions	O
.	O
</s>
<s>
Peripherals	O
,	O
such	O
as	O
a	O
keyboard	B-Device
,	O
mouse	B-Device
and	O
monitor	B-Device
,	O
almost	O
always	O
must	O
be	O
acquired	O
separately	O
.	O
</s>
<s>
Barebone	O
systems	O
sometimes	O
include	O
a	O
graphics	B-Architecture
processor	I-Architecture
or	O
RAM	B-Architecture
,	O
but	O
rarely	O
any	O
mass	O
storage	O
media	O
(	O
hard	B-Device
drives	I-Device
)	O
,	O
operating	B-General_Concept
system	I-General_Concept
or	O
other	O
software	O
.	O
</s>
<s>
Sometimes	O
PCs	O
with	O
everything	O
a	O
normal	O
desktop	B-Device
PC	I-Device
has	O
except	O
Microsoft	B-Application
Windows	I-Application
operating	I-Application
systems	I-Application
are	O
sold	O
as	O
a	O
barebone	B-Device
computer	I-Device
,	O
but	O
may	O
include	O
free	B-Application
software	I-Application
such	O
as	O
Linux	B-Application
.	O
</s>
<s>
Refurbished	O
and	O
used	O
computers	O
may	O
also	O
be	O
repackaged	O
as	O
barebone	B-Device
computers	I-Device
,	O
as	O
many	O
computers	O
returned	O
for	O
refurbishing	O
may	O
have	O
missing	O
,	O
broken	O
,	O
or	O
obsolete	O
parts	O
such	O
as	O
hard	B-Device
drives	I-Device
and	O
peripherals	O
.	O
</s>
<s>
Future	O
upgradeability	O
of	O
a	O
barebone	O
system	O
may	O
be	O
limited	O
,	O
especially	O
the	O
motherboard	B-Device
component	O
,	O
which	O
may	O
have	O
less	O
space	O
for	O
extra	O
I/O	O
devices	O
and	O
fewer	O
memory	O
and	O
PCI	B-Protocol
card	I-Protocol
slots	O
than	O
desired	O
.	O
</s>
<s>
The	O
motherboard	B-Device
may	O
not	O
be	O
compatible	O
with	O
faster	O
processors	O
and	O
memory	O
than	O
those	O
originally	O
purchased	O
with	O
the	O
barebone	O
system	O
.	O
</s>
<s>
Barebones	O
may	O
also	O
have	O
limit	O
on	O
the	O
maximal	O
processor	O
thermal	B-General_Concept
design	I-General_Concept
power	I-General_Concept
(	O
TDP	O
)	O
and	O
not	O
be	O
able	O
to	O
support	O
CPUs	O
that	O
would	O
otherwise	O
fit	O
into	O
the	O
socket	O
.	O
</s>
<s>
The	O
following	O
companies	O
currently	O
manufacture	O
barebone	B-Device
computers	I-Device
:	O
</s>
