error ME516-5W, HP, IQ815 Touchsmart?

I don't know what diagnostic tool you use, but the names of the tests and error codes suggest some memory related errors. Those are low level tests that don't use the OS at all. In fact, the OS is probably not even loaded during those.

Some possible causes:
Excessive overclocking.
Memory timing is to short/fast.
Dirty contacts.
Bad memory modules.

The first 2 can be corrected by adjusting the BIOS settings.
Set system speen at it's nominal, or default, speed.
Set the memory timing at default, as provided by the memory modules. (in my case, it read "As SPD")

If that don't correct the problem, to as follow:
1 - Unplug the computer's power cord. Press the power button for 1 or 2 seconds. (this dischage the various capacitors faster)
2 - Open the case.
3 - Find the memory modules.
4 - Remove them using the clips on each ends.
5 - Put the modules back. Press firmly straight down untill the clips snap back into closed position. You may swap the modules from a given bank.
6 - Close the case, plug the computer and start the computer.

If you still get the errors, then it's that you have some bad memory modules that need to be replaced. If you have memory in more than 1 bank, you need to fing whitch bank have bad a module.
Remove all modules except for a single bank and perform the tests.
If you still have the errors, remove the modules you just tested, that you know is bad.
Install a bank that you removed and repeat the test.

If you have dual channel memory, both modules from a given bank MUST be changed using a new matched pair.

NEVER remove or replace only a single memory module if you have dual or tripple channel memory. They MUST be installed as matched kits completely filling a single bank.

The sockets are colour coded. One bank is usualy black, another may be is brown or blue or red, or white/gray...

I don't think that you have any geristry problem. The registry is never accessed during those low level tests.
It don't look as driver related. Several system diagnosis tools use a special minimal bare bones OS to do the tests. Your drivers are not loaded during those tests, especialy the memory tests.

Electro
October 2011

If you haven't gor a good Registry Cleaner....Go Here:
http://www.piriform.net

fedup
October 2011

It could be bad Ram that needs removing or Driver Errors that need fixing. Does the PC crash? Have you done a full virus scan? Try this and yes it's free.....I take No Responsibilty for what may/may not happen!

http://pcerrorhelp.net/repair-errors/
If this does not do the trick...there's a man on here called Electo....Ask him to solve the prob!

fedup
October 2011