Error Hi, While installed the Virtual pc and open the same in the dell gx520 this error will appear -get a solution. Virtual pc is incompatible with PAE mode. This version of virtual pc cannot runwith PAE(physical address Extntion)mode enabled on the host.please disable this feature before running virtual pc again.

SOURCE: NSIS Error. Error Launcging Installer

hi,
this is a common problem.
use revo uninstaller to completely remove the program
and download adobe flash player from
www.filehippo.com.  this should solve your problem.Its probably jus a minor installer problem

and if i helped u solve ur problem in any way...please help me by clicking on the fixya rating. 
thank you.

SOURCE: GX520 screen display message: cannot display this video mode

This means that the windows setting you have set can not display on your current monitor. There are two ways to fix this, one is to boot the computer in safe mode by pressing f8 after the POST screen and change the resolution and the other is to plug the computer into a different monitor to see if supports that resolution and then change the resolution in windows to a lower setting.

In case you don't know how to change the resolution in windows, follow below.

Right click on the desktop
Properties
Settings at the top
Move the slider to 1024x768
Click ok

Try rebooting. If that still doesn't work, try another resolution.

SOURCE: i need an audio device for my dell desktop optiplex gx520 install

you can go to dells website and click support drivers and downloads type in the service tag of the machine (its 7 letters and nubers found on CPU Ex: BF14FJ1) and based on the service tag the correct audio drivers should be displayed for you to download.