When turning on the PC while the System starts up and the Zorin Logo appears, then screen flickers and the system takes a long time to start up unless you touch Tab and it stops
I have looked for the solution in other forums, but they only give me the solution for laptops with Nvidia and my Laptop has no graphics card.
While the screen is flashing, the processes that are starting appear and it takes a long time
Well that would be a problem. 
I do not know which Zorin you are using on what spec machine, but my Zorin 16 Pro indeed takes a bit of time to boot. It does not bother me since I usually go to the kitchen and make myself a morning espresso during that time 
yes I believe it to be drivers as flickers sometimes mean drivers or onboard graphics can't handle the load. IMO @Jesusito what is your system specs and what version of Zorin
Good point.
As far as I know, most Intel GPU drivers should be included in the kernel.
@Jesusito
Can you issue this command in terminal?
lspci
I use Zorin Os 16 I have 12GB of RAM and an I5-6200U CPU and Intel HD Graphics 520
00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Host Bridge/DRAM Registers (rev 08)
00:02.0 VGA compatible controller: Intel Corporation Skylake GT2 [HD Graphics 520] (rev 07)
00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21)
00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI #1 (rev 21)
00:17.0 SATA controller: Intel Corporation Sunrise Point-LP SATA Controller [AHCI mode] (rev 21)
00:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #5 (rev f1)
00:1c.5 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #6 (rev f1)
00:1d.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #9 (rev f1)
00:1f.0 ISA bridge: Intel Corporation Sunrise Point-LP LPC Controller (rev 21)
00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21)
00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21)
00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21)
01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter
03:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader (rev 01)
You should add this info to your Profile so that volunteers do not have to ask you a same question repeatedly.
I did not know that this could be done 
One year ago, someone complained a regression of the kernel with this GPU performance:
The only thing I can think of is booting from the previous stable kernel and see if it helps.
@Jesusito have you tried : sudo apt update & sudo apt upgrade ?
And does it only flicker at bootup when the Zorin logo shows? you mentioned Ubuntu logo ....
I have no update
Yes, it only flashes while the system is booting, once it finishes loading the system, the problem stops
I think this is just the way it appears at load up. It could be construed as a issue when it's just the logo I call heartbeat. If your system runs fine I believed it's solved
I think so too.
@Jesusito
There is really nothing to worry about if the system runs normal after booting.
It doesn't work quite right, graphics performance after that is fatal
Ah, OK you do have a problem.
I will ask @Aravisian if you can go back to the older stable kernel.
Did you tried my suggestion? Please let us know.
Yes, but I don't install anything
I think you need to downgrade kernel to 5.8 or 5.4 to see if that makes any difference
