Sharing my experience with OS X Lion on
HP Compaq DC7800 Ultra Slim Desktop
At this time 23/01/2013 the system cost about £80.00 pounds from eBay second hand, With added second hand memory £130.00 pounds. Also i have added an Low Profile ATi Radeon 5450 - 512MB card giving it 1080p (Google or Search this Forum of that Driver.) Total £160.00
Intel Core2Duo 2.66GHz
8GB DDR2 SDRAM 800MHz RAM (Upgraded from 1GB)
160GB 7200RPM SATA1 Hard DriveOk. Here we go...
1) Grab a copy of iAtKOS L2 and put it on a DVD 4.7G (Also purchese a copy of OS X Lion too!)
2) Once you get past the initial setup for your language choice and the menu bar is present, select to run Disk Utility under the Utilities menu if you need to setup the hard drive.
3) Once the hard drive has been prepared, click Continue to go to the next section. Click Agree to the terms of the software license agreement to continue and select the hard drive where you wish to install Lion on.
4) Click the Customize button and select the following options:
Under Drivers>Main Hardware>SATA/IDE: Select Non-AHCI SATA
Under Drivers>Main Hardware>Sound>VoodooHDA: Select v2.1 (Not the latest version!)
Under Drivers>Network>Wired: Select Intel Gigabit
Hardware Senors: > CPU
LEAVE ALL OTHER OPTIONS
5) Click OK, then click Install. Sit back and relax, Lion will be installed. Remove the DVD from the drive and reboot when it is finished.
6) When installed and rebooted, Go to the Apple logo at the top left, Hit Software Update, Leave everything ticked but not Java Update!!!!!, At this time the update is roughly 2.29GB