Every miner can only confirm transactions. Acceleration just means that they will give priority to your transaction in the next block they mine which for big miners is every couple of hours.
I am unfamiliar with "Windows Bitcoin Miner" and most are just malware. You can't just download a miner anymore, you need to buy special hardware in order to do any Bitcoin mining. I would suggest that you reinstall your OS as your computer is probably infected with malware (then again which PC that is running Windows isn't ? ).
As I said, one guy accelerated my transaction, as he said (I can't check it out, what exactly happened with my transaction). But what I see that it is still unconfirmed. So he said he gave prio to my transaction. Why do you say that every miner can only confirm? Direct after that you explain about an acceleration. But it is not the same as confirmation, isn't it?
So if I buy special hardware, can I at least confirm my own transaction, and I mean confirm not simply accelerate? (I read that profitability of the mining is very unpredictable, that's why I written 'at least'). What are minimal requirements for this hardware? Does this hardware contain all needed software as well?
(I have a Norton Antivirus. E.g. MinerGate Software was as malware identified and removed. But on Windows Miner, it didn't react.)