Hard drive space .......or lack of!!!!

[codswallop]

Some while back I purchased an external h/drive to make a copy of what's on my PC,below are the readings of available space:-
PC.....original space 590 GB...now available 334 GB 56%
Ext H/drive ditto 466GB ditto 78 GB 16%
Can anyone please explain the difference in the percentages?
I'm obviously overlooking something,if anything I would have thought it might be the other way round %wise.Thanks!!!!

[squarebear]

Seems ok to me. You can't back certain system files up unless you use special tools and so the amount of free space will never equal what's on your PC.

[codswallop]

Thanks sb,that's disappointing,not what I wanted to hear.Considering my main "storage items"are photos and not thousands of them either,it seems like I'll forever be buying external h/drives!!!!

[ChuckFickens]

It doesn't seem correct to me...

you've obviously got around 250GB of information on your computer drive in total (including programs and the system) yet you seem to have managed to put about 388GB of data onto your external hard drive.

As long as there is nothing on the external hard drive that isn't on your computer I'd format the external drive to totally wipe it and then copy your files (photos etc) over to the drive again.

[scowie]

78 out of 466 is 16%
334 out of 590 is 56%

seems fine to me

[codswallop]

Thanks for your replies. Chuck that was the sort of answer I was hoping to get ,but afraid of, because of my limited PC skills.I have a recovery disc that came with the PC.If the worst came to the worst would that revert the computer as to the day I bought it??And then add progs.that I've acquired in the mean time?(assuming I still have the CD's)If I went the formatting way,on the ext.h/drive, is there any way of selecting these extra bought progs.so that they don't get formatted as well??? A bit long winded,but that's me you didn't want it easy did you?????????