@BillK,
>But if it is supposed to make old PCs run faster, shouldn’t it be able to run on Windows XP?
I think you mis-read what the statement says. It states “Makes old PCs live longer” (not faster).
It makes “New PCs run faster” (as in run away)
Old PCs cannot really use this software (to install, PCs must be less than 8 years old (since Windows 7 came out, 2009)). I cannot consider that old.
The reason the Old PCs live longer is because old PCs, such as those that have XP, cannot be infected by this software.
After many years using, programming, and maintaining PCs, I have attempted to test and use AVG products whenever something new came out, but not any more.
AVG, having been in the AntiVirus business, has used some of the tricks of the viruses. I found that one of their products that was intended to protect your web browsing, had multiple hooks to prevent its removal (remove one hook, it gets repaired). It could not be removed through the common Programs Uninstall list. Their online help steps to remove the software merely insured that it was installed with all its hooks re-instated. At that point, I no longer risk or recommend using any of the AVG products, no matter how fantastic they may be now.
I do not know if this product can be un-installed easily, or do I know if it works well.
Thankfully there are many alternative to anything in their product line.