hi friends i have mac ibook g4 i know its a really old model but its perfectly fine it has installed mac os x 10.5.8 ok whenever i copy and paste any thing it says no free space weather i copy from folder to desktop or from usb to mac plz help plz

How much free room do you have left on your hard drive?

And, just asking, have you emptied the Trash lately?

There is no download for 10.4.x or 10.5.x, there is a very slim chance you can get 10.5 by calling Apple, but usually you can only get it on eBay & such.

Tiger Requirements...

To use Mac OS X 10.4 Tiger, your Macintosh needs:

* A PowerPC G3, G4, or G5 processor

* Built-in FireWire

* At least 256 MB of RAM (I recommend 1GB minimum)

* DVD drive (DVD-ROM), Combo (CD-RW/DVD-ROM) or SuperDrive (DVD-R) for installation

* At least 3 GB of free disk space; 4 GB if you install the XCode 2 Developer Tools (I recommend 20GB minimum)

http://support.apple.com/kb/HT1514

http://www.ebay.com/sch/i.html?_nkw=mac+os+x+tiger+retail+10.4

See Tom's, (Texas Mac Man), great info on where/how to find/get Tiger...

https://discussions.apple.com/thread/3089008?answerId=15305521022#15305521022

Or Ali Brown's great info on where/how to find/get Tiger...

http://discussions.apple.com/thread.jspa?messageID=10381710#10381710

Leopard requirements/10.5.x...

* Mac computer with an Intel, PowerPC G5, or PowerPC G4 (867MHz or faster) processor

minimum system requirements

* 512MB of memory (I say 1.5GB for PPC at least, 2-3GB minimum for IntelMacs)

* DVD drive for installation

* 9GB of available disk space (I say 30GB at least)

Classic/OS9 Apps no longer supported.

May be available from Apple again...

https://discussions.apple.com/thread/4720126?tstart=0

Trouble is Apple no longer sells it, check eBay & such for the Retail version, not the Gray Discs...

http://www.ebay.com/sch/i.html?_nkw=mac+os+x+leopard+retail+10.5

Now, for your Trash problem, see if this helps...

Solving Trash Problems...

http://thexlab.com/faqs/trash.html