|"So my computer recentely stuffed up ..."|
Did you do anything else, such as install Windows from scratch ?
If you DID install Windows from scratch, the hard drive(s) and optical drives may not run at their full speed until AFTER you have loaded the main chipset drivers.
Whenever you load Windows from a regular Windows CD (or DVD) from scratch, after Setup is finished you must load the drivers for the mboard, particularly the main chipset drivers, in order for Windows to have the proper drivers for and information about your mboard hardware, including it's AGP or PCI-E, ACPI, USB 2.0 if it has it, and hard drive controller support. If you have a generic system and have the CD that came with the mboard, all the necessary drivers are on it. If you load drivers from the web, brand name system builders and mboard makers often DO NOT have the main chipset drivers listed in the downloads for your model - in that case you must go to the maker of the main chipset's web site, get the drivers, and load them.
Load the main chipset drivers first.
Lots of things can cause Windows to run slower than it should.
One of those things is if there isn't enough free space on C, Windows will slow down.
What's the size of your C partition, and how much much free space does it have ?
When you have already installed the software for a previous video adapter, you're supposed to install the software for a new video adapter only AFTER Windows has been set to a default VGA mode of some sort. Un-installing the previous video drivers and software listed in Add/Remove Programs BEFORE you install the software for the new video adapter does that automatically.
I know from experience that if you did not un-install the software for the previous video before you installed the software for the Radeon adapter, the software for the new Radeon card probably will NOT install properly.
If you did NOT un-install the software for the previous adapter before you installed the software for the Radeon adapter
- go to Add/Remove Programs and un-install all the listings for the Radeon adapter, and if that's still there, all the graphics related software for the previous video adapter, THEN install the software for the Radeon adapter.
DO NOT choose to install video drivers for the Radeon card while booting the computer, before the software for the device has been installed, when Windows detects a device while booting - CANCEL that, and continue on to thedesktop, then use the proper installation program on the CD that came with it, or use the proper software installation program you you got from the web.
If you DID install drivers for the Radeon card while booting the computer, before the software for the device had been installed, Windows probably did not install the software for the device properly, because video software installations always have other associated programs that must be installed along with the drivers - installing just the drivers while booting into Windows results in the software NOT installing properly.
Go to Control Panel - Classic View - Add/Remove programs, an Un-install all listings for the device, then install the software for it properly .
( On the other hand, you don't necessarily have to install Catalyst - you can choose a Custom or similar installation when you use the CD that came with it, and choose to not install it. )
I'm assuming the ATI Radeon HD 4300/4500 is a PCI-E X16 card.
Go into your mboard's bios Setup and make sure the setting Primary Video or Initialize Video First or similar is set to PCI-E or similar. If that seting is not correct, the video still works in Windows, but the enhanced features that Windows normally enables when Windows knows it's PCI-E adapter, that are supported by the specific drivers loaded for the video chipset, will probably not work properly.