Q: I have a g4 ibook 2005 that keeps demanding a restart

If you mean the four language screen, that's a Kernel Panic.  If an erase and install with no peripherals attached causes it there are a couple more possible causes:

1. The wrong installer disc.  That Mac could only use the 10.4.2 installer disc prebundled with it called iBook G4, the 10.4.3 or 10.4.6 retail shown in this tip:

https://discussions.apple.com/docs/DOC-2541

or one of the 10.5 retail discs shown in this tip:

https://discussions.apple.com/docs/DOC-2275

2. Bad or incompatible internal hardware.  That particular model took: 333 MHz PC2700 DDR SDRAM according to specs, however, not all notebook RAM of that spec is compatible.   And some just fails.    http://www.datamem.com/ http://www.crucial.com/ and http://www.macsales.com/ (OWC) let you specify mid-2005 iBook G4.  Only RAM that you ask for mid-2005 iBook G4 is compatible, and should only be gotten in lifetime warranty, and not ValueRAM style either.

You can use the prebundled hardware test to detect some bad RAM, but not all.    This address lets you get that disc, if AppleCare no longer has it in stock:

https://github.com/upekkha/AppleHardwareTest

Once you start adding non-Apple hardware or software, all bets are off as to the cause of the kernel panic.  If you have only one copy of your data, read this tip on data recovery, and make sure the disc is a combination of the 10.4.3, 10.4.6, or 10.5 retail disc and data recovery software, or install one of those on an external hard drive, and it is PowerPC compatible.  Intel Mac only data recovery software will not work with your Mac.

https://discussions.apple.com/docs/DOC-1689

A contributing cause of kernel panic  in hardware may be a failing hard disk drive

or a failed on-board RAM chip that is not user replaceable. The soldered-in chip

on your iBook (12-inch or 14-inch) mid 2005 would be a 512MB and the upgrade

to add more, a PC2700 DDR333 SO-DIMM 1024MB; the same exact chip that

an iMac G4 USB2.0 series would use, for its user-upgrade chip. Of high quality.

If you had an externally enclosed hard disk drive in self-powered FireWire enclosure

and an Oxford-type chipset to guaranty that it would be capable of booting an OS X

system with a PowerPC architecture Mac computer, then you could see if a system

could be installed or cloned to such an external HDD for testing purposes and also

as a backup, to make a bootable copy should the internal drive be going bad, too.

The causes of kernel panics are a few; troubleshooting and diagnostic efforts can

take a bit of time and be rather tedious. Sometimes, not resolvable by the end user.

•The XLab: resolving Kernel Panics

http://www.thexlab.com/faqs/kernelpanics.html

•Technical Note TN2063: Understanding and Debugging Kernel Panics:

https://developer.apple.com/library/mac/technotes/tn2063/_index.html

The hardware test may or may not provide usable result, but that is a matter of

troubleshooting by use of any or all tools to see what can come from them. In

some models of iBook G4 there were issues that involved logic board failure.

Good luck & happy computing!